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Biochem NBME > Genetics > Flashcards

Genetics Flashcards

1
Q

Start vs Stop Codons
“U Go Away, U Are Away, U Are Gone”

A

AUG (MET)
UGA, UAA, UAG

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2
Q

Process of protein synthesis key points

Initiation
Elongation
Termination

A

Initiation:
–> eIF id 5’cap & assemble 40S, eIF’s release & 60S is assembled with ATP (Chraging) & GTP (Translocation)

Elongation:
–> Aminoacyl-tRNA binds A site & rRNA catalyzes growing peptide bond + adds peptides

–> Ribosome moves 3 nucleotides to 3’ end or mRNA bringing the tRNA to P site

Termination:
–> eRF’s id stops codon & stop translation, the finished polypeptide is released (via GTP) from E site

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3
Q

APE of protein synthesis

A

A: Aminoacyl-tRNA
P: Peptide grows
E: Empty tRNA Exits

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4
Q

Shine-Daigarno sequence

A

A prokaryotic ribosomal binding site that aligns ribosomes to a start codon

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5
Q

Which bacteria target eIFs in protein synthesis via bacterial endo/exotoxins to interfere with protein formation?

A

Diptheria & Pseudomonas

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6
Q

Post Translational Modification

Trimming

Covalent alteration

Chaperone

A

Trimming:
–> Remove N or C terminal peptides to make a mature protein

Covalent Alt:
–> Phosphorylation, Hydroxylation, Glycosylation, methylation, acetylation, & ubiquitination

Chaperone:
–> Intracellular proteins to facilitate/maintain protein folding/denaturation (heat shock proteins in yeast)

Ex. Cystic fibrosis

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7
Q

Cell types:

Permanent

Stable/Quiescent

Labile

A

Perm:
Stuck in G0 (neurons, skeletal, cardiac, RBC)

S/Q:
Can go from G1–>G0 ( Hepato, lympho cytes, PCT, Periosteal cells)

Labile:
Always dividing ( Bone marrow, gut epi, skin/hair/germ cells)

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8
Q

Cell cycle

&

Regulators (3)

A

Reg:
Cyclin-dep kinases
Cyclin-CPK complexes (Phosphorylate Rb)
Tumour suppressors (P53)

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9
Q

Cell Trafficking (RER—> Golgi) processes

COPS I&II Function

A

“2 steps forward, 1 step back”

COPII –Anterograde–> Cis Golgi –> Trans golgi–> Lysosomes (destroyed) OR plasma membrane (via LDL receptors)

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10
Q

RER

VS.

SER

What’s made & gen characteristics?

A

RER:
Secretory hormone synthesis
N-linked oligosaccharide addition to lysosomal proteins
Nissle bodies to make peptide neurotransmitters

SER:
Steroid hormone synthesis
Detox site
Has Glu-6-phosphatase (glycogenolysis/gluconeogenesis)

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11
Q

O-Oligosaccharides functions (3)

A
  • N-oligosaccharide on asparagine
  • Adding O-oligosaccharide on serine+threonine
  • Adding Mannose-6-phosphate to proteins
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12
Q

Lysosomal Storage disorders: AR

Lysosomal enzyme deficiency accumulation of abnormal metabolic products.

A

I cell disease
Fabrys
Gauchers
Krabes
Metachromatic leukodystrophy
Nieman Picks
Tay Sachs

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13
Q

Peroxisome associated disorders

A

Zellweger syndrome
Refsum disease
Adrenolenkodystrophy

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14
Q

I-Cell disease

A

Def N-acetylglucoasminyl-1-phosphotransferase reduces mannos-6-phosphaste

Lysosomes lack enzymes to break shit down causing a build-up of debris & high levels of lysosomal enzymes in the blood

Signs:
Coarse facial hair
Gingival hyper plasia
Corneal clouding
Claw hand
Kyphosis
Fatal in childhood

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15
Q

Zellweger syndrome

A

AUTO REC
Mutated PEX genes

Signs:
Hypotonia
Seizures
Hepatosplenomegaly
Early death

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16
Q

Refsum disease

A

AUTO REC
Def a-oxidation & high phytanic acid

Signs:
Scaly skin
Ataxia
Cataracts/Night blindness
Short 4th toe
Epiphyseal displacement

Rx Diet + plasmapheresis

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17
Q

Adrenoleukodystrophy

A

X-linked
Mutated ABCD1 gene =
Disordered B-oxidation causing high levels of very-long-chain fatty acids in adrenals

Signs:
White (leuko) matter in brain & testes
Adrenal crisis
Progressive loss of neurological function
Death

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18
Q

Cytoskeleton features

Microfilaments

Intermediate filaments

Microtubes

A

Microfil:
–> Muscle contraction, cytokinesis, actin, & microvilli

Int:
–> Cell structure, vimentin, desmin, & laminins,

Microtubules:
–> Movement (cilia, flagella, mitotic spindle) & axonal trafficking centrioles

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19
Q

Dynein vs Kinesin

“REaDY? AttacK!”
“Negative Near Nucleus, Positive Points to Periphery)

A

Retrograde + —> - via dynein

Anterograde - —> + - via kinesin

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20
Q

Which bacteria/viruses (3) use dynein for retrograde transport to the neuronal cell body?

A

C. tetani, Poliovirus, & HSV

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21
Q

Medications that act upon microtubules
“Microtubes Get Constructed Very Terribly”

A

Mebendazole (anthelminthic)
Griseofulrin (antifungal)
Colchicine (anti-gout)
Vinca alkaloids (anti-cancer)
Taxanes (anti-cancer)

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22
Q

What type of cellular junction allows coordinated ciliary movement?

A

Gap junctions

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23
Q

Kartagener syndrome
“Kylie Jenner can’t shake ass”

A

AUTO REC
Dynein arm defect = immobile cilia

Signs:
Developmental delays
Hearing loss
Recurrent infections
Infertility

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24
Q

Sodium-potassium pump works by moving.

What cardio glycosides directly inhibit the NA/K pump, thereby indirectly increasing heart contractility

A

2 K+ in
3 Na out

Digitoxin & Digoxin

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25
Q

Collagen types
1,2,3,4
“SCAB”

A

I: Skeleton (Bone, tendon, skin) –> Osteogenesis imperfecta 1

II: Cartilage (hyalin)

III: Arteries –> Elhers-Danlos (threED)

IV: Basement membranes –> Alport syndrome + GoodPastures

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26
Q

Collagen synthesis process

Collagen synthesis disorders

A

Scurvy (vit C)
Osteogenesis imperfecta
Menkes

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27
Q

Scurvy

A

Vitamin C deficiency:
Can’t hydroxylate proline/lysine for collagen synthesis
Tea and toast diet

Signs:
Swollen gums
mucosal bleeding
poor wound healing
petechiae

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28
Q

Osteogenesis imperfecta
“BITE”

A

AUTO DOM
Defective COL1A1 or COL1A2 gene = alters the triple helix formation of collagen.

Bones (many fractures/deformities)
I (eye, Blue sclera)
Teeth (dental imperfections)
Ear (Conductive hearing loss

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29
Q

Elher-Danlos syndrome

A

AUTO DOM/REC

Classical: def V collagen (basement membranes)
- Hypermobile joints
- Hyperflexible skin
- Easy bruising
- Mutated CO5A1 or COL5A2

Vascular: def III collagen (Arteries)
- Berry aortic aneurysm
- Muscle/organ/artery are rupture-prone
-Mutated COL3A1

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30
Q

Menkes Disease

A

X-linked REC
Defective ATP7A gene causing low Cu2+ to be present for lysyl oxidase

Signs:
Brittle-Kinky hair
Developmental delay
Hypotonia
Risk of cerebral aneurysms

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31
Q

Goodpasture syndrome

2 complications

A

The linear appearance of IgG deposition on glomerular and
alveolar basement membranes

Can cause:
Glomerulonephritis and hemoptysis via Anti–glomerular basement membrane antibodies

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32
Q

Elastin is different from collagen due to the high amounts of what?

A

Unhydroxylated proline, glycine, & lysine residues

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33
Q

How does aging impact collagen, elastin, & cross-linking levels?

A

Collagen & elastin synthesis is reduced

Cross-linking levels stay normal

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34
Q

Marfan’s Syndrome
“FFF”

A

AUTO DOM
Mutated chromosome Fifteenth on the FBN1 gene
Defective Fibrillin

Signs:
“MARFANS”
Main:
*Tall/long arms/flat feet
*Mitral regurgitation
*Aortic root aneurysm
* pNeumothorax
*Arachnodactyly
Hypermobile joints
Up/out lens dislocation

Other:
Pigeon chest
Mitral valve prolapse

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35
Q

Homocystinuria

A

AUTO REC

Signs:
*Joint Hyperlaxity
*Skin hyperelasticity
*Down/out lens dislocation
* Thrombosis
* Impaired intellect

Other:
Pigeon chest
Scoliosis
Tall/long arms
Arachnodactyly

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36
Q

Blotting
“SNoW DRoP”

A

Southern:DNA (Pedigrees)

Northern: RNA (mRNA/gene expression)

Western: Proteins (labelling antibody to find proteins)

SouthWestern: DNA-binding proteins (Leucine zipper motif/DNA probes)

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37
Q

Flow cytometry

A

Assess the size, granularity, & protein expression.

i.e Leukemia, paroxysmal nocturnal hemoglobinuria, & fatal RBCs) & Immunodeficiency (HIV/AIDs)

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38
Q

Microarrays

A

Compares the expression of genes in two diff samples i.e SNP u CNVs (copy # variants)

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39
Q

ELISA

A

Tests for specific antigens/bodies
i.e HIV

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40
Q

Karyotyping

A

Colchicine stops chromosomes in metaphase

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41
Q

Fluorescence in situ hybridization:

Microdeletion
Translocation
Duplication

A

Microdeletion: no fluorescence on an X
Translocation: Fluorescence signal of one X on another X
Duplication: Trisomy (XXX)

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42
Q

Gene expression modification

A

Knock in
Knock out
Random insertion (constitutive expression)
Targeted insertion (conditional expression)

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43
Q

RNA interference

microRNA

small interfering RNA

A

miRNA: Hairpin structures that block translocation & increase degradation of mRNA (Suppressing P53 mRNA = Tumor malignancy)

siRNA: Specific mRNA targeting, meaning it cleaves mRNA before translocation (knockdown exp)

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44
Q

Genetics

Codominance

Variable expressivity

Incomplete penetrance

Pleiotropy

A

Codominance: Both alleles influence the phenotype
- Blood types
- a-Antitrypsin def
- HCA groups

Variable exp: Persons with the same genotype express the mutant phenotype
-Neurofibromatosis type 1

Incomplete pen: Not all people with the genotype express the mutant phenotype
- BRCA1 gene (only always breast/ovarian cancer)
%penetrance x inheritance probability = risk of phenotype

Pleiotropy: One gene contributes to many phenotypes
- PKU (light skin, intellectual disorder, & musty odour)

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45
Q

Genetics

Anticipation

Loss of heterozygosity

Dominant Neg mutation

A

Anticipation: worse severity/earlier onset of a disease in upcoming generations (trinucleotide repeats)
- Huntingtons

Loss of heterozygosity: Patient/develops a mutation in the tumor suppressor gene, then the wild-type gene needs to be deleted as well
- Cancer
- Retinoblastoma
- Lynch syndrome
- Li-Fraumeni syndrome

Dom Neg Mut: Heterozygote makes a non-functional altered protein that prevents the normal gene product from working
- 1 Mutated P53 = Protein binds DNA & blocks non-mutated P53 from binding the promoter)

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46
Q

Genetics

Linkage disequilibrium

Mosaicism

A

Linkage disequilibrium: Certain alleles at 2 linked loci happen more/less often than expected

Mosaicism: Genetically distinct cell lines in the same person, Somatic (mutation via mitotic errors post-fertilization) & Gonadal (mutation ONLY in egg or sperm) PICTURE

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47
Q

Hardy Winberg Equations

AA
Aa
aa
X-linked Rec

A

AA= P^2
Aa= 2Pq
aa= q^2

X-REC:
Male q
Female q^2

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48
Q

Imprinting disorders:

Prader-Willi Syndrome
“POP”

A

Deleted Maternal genes & deleted or mutated Parental X15

Signs:
Obesity
Hyperplasia
Intellectual disability
Hypogonadism
Hypotonia

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49
Q

Imprinting disorders:

Angelman Syndrome
“MAMAS”

A

The paternal UBE3A gene is silenced & maternal allele is deleted/mutated on X15.

Signs:
Ataxia
Inappropriate laughter
Intellectual disability
Seizures

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50
Q

Modes of inheritance:

A

AUTO DOM (1/2 Aa-aa, or 3/4 Aa-Aa)

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51
Q

Modes of inheritance :

A

AUTO REC
parents both A/a =1/4 aa, 1/4AA, 1/2 Aa

Note is a person’s sibling is aa their chance of being A/a is 2/3

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52
Q

Mode of inheritance:

A

X-linked REC

Mom –> son 50%
No dad –> son

Usually effects males

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53
Q

Mode of inheritance:

A

X-linked Dom

Mom –> all 50%
Dad –> Daughters

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54
Q

Mode of inheritance:

A

Mitochondrial inheritance

From mom —> daughters 50%, sons 100%

Affected daughters offspring 100% phenotype

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55
Q

Mitochondrial inheritance disorders

A

MELAS & Leber Hereditary optic neuropathy

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56
Q

MELAS (Mitochondrial encephalopathy lactic acidosis & stroke-like episodes)

A

*RAGGED-RED FIBERS
Myopathy
Lactic acidosis
CNS issues

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57
Q

Leber Hereditary Optic Neuropathy (LHON)

A

Subacute bilateral vision loss
Neurological dysfunction
Cardiac conduction defects

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58
Q

List of AUTO DOM diseases:
A
A
F
F
H
H
H
L
M
M
M
N
N
T

A

Achondroplasia
Autosomal dominant polycystic kidney disease
Familial adenomatous polyposis
Familial hypercholesterolemia
Hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu
syndrome)
Hereditary spherocytosis
Huntington disease
Li-Fraumeni syndrome
Marfan syndrome
Multiple endocrine neoplasias
Myotonic muscular dystrophy
Neurofibromatosis type 1 (von Recklinghausen disease)
Neurofibromatosis type 2
Tuberous sclerosis,
von Hippel-Lindau disease

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59
Q

List of AUTO REC Diseases:
“Oh, Please! Can Students Who Score High Grades Tell Me Features of the Kidney disorder Autosomal Recessive Polycystic Kidney Disease? “

A

Oculocutaneous albinism
Phenylketonuria
Cystic fibrosis
Sickle cell disease
Wilson disease
Sphingolipidoses (except Fabry disease)
Hemochromatosis
Glycogen storage diseases
Thalassemia
Mucopolysaccharidoses (except Hunter syndrome)
Friedreich ataxia
Kartagener syndrome
ARPKD (Auto REC Polycystic Kidney Disease)

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60
Q

X-linked REC disorder list:

B
D/B
G
H
H
L
O
O
O
W

A

Bruton agammaglobulinemia
Duchenne and Becker muscular dystrophies
Fabry disease
G6PD deficiency
Hemophilia A and B
Hunter syndrome
Lesch-Nyhan syndrome
Ocular albinism
Ornithine transcarbamylase deficiency
Wiskott-Aldrich syndrome

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61
Q

Cystic Fibrosis

A

AUTO REC
Defective CFTR on X7 with a commonly deleted Phe508 (Europeans esp)

Signs:
Recurrent pulmonary infections
Nasal polyps
Pancreatic insufficiency
Infertility
Positive Cl- sweat test

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62
Q

Duchenne Muscular Dystrophy

A

X-linked REC (usually frameshift mutations)
Deleted Dystrophin

Signs:
Weak pelvic girdle muscles
Calve pseudohypertrophy
Dilated cardiomyopathy
Growers sign (needs hands to stand up)
Lordosis
High Creatine Kinase & Aldolase llevels

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63
Q

Becker muscular dystrophy

“Becker is Better” less severe.

A

X-linked (non-frameshift mutation)
Partially functional dystrophin

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64
Q

Myotonic dystrophy
“CTG”

A

AUTO DOM
Onset 20-30yrs
Trinucleotide repeats

Signs:
CTG (Cataracts, Toupee (male balding, Gonadal atrophy)
Arrhythmia
Myotonia
Muscle wasting

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65
Q

Rett Syndrome
“retturned”

A

Usually impacts females (males die in utero) on the X chromosome
onset age 1-4yrs

Signs:
Regression of motor, verbal, and cognitive abilities
Ataxia
Seizures
Hand wriggling

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66
Q

Fragile X Syndrome

A

X-linked DOM
Trinucleotide repeats in the FMR1 (CGG repeat during oogenesis)

Signs:
Intellectual disability
(50-200 repeats) - premature (tremor, ataxia, primary ovarian insufficiency)
(>200 repeats) - full mutation (post-pubertal macrochidism, long face, large jaws, large/high ears, hypermobile joints, & self mutilation)

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67
Q

Trinucleotide repeat disorders:
Show genetic anticipation with high disease severity & lower age of onset

A

Huntingtons (CAG)
Myotrophic dystrophy (CTG)
Fragile X Syndrome (CGG)
Friedrich ataxia (GAA)

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68
Q

AUTO trisomies:

Down Syndrome

A

AKA Trisomy 21

Markers (Hi)
- High hCG & inhibin

5 A’s
Advanced maternal age (risk)
Atresia (duodenal)
Atrioventricular septal defect
Alzheimers (early-onset)
AML/ALL (X21 encodes amyloid precursor protein)

Other signs:
Single palmar crease
Hirchsprungs disease
Brush field spots (white spots in the iris peripheral)
Intellectual disability

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69
Q

AUTO trisomies:

Edwards Syndrome (18)
“PRINCE-edwards”

A

Prominent occiput
Rocker-bottom feet
Intellectual disability
Non-disjunction
Clenched fists/overlapping fingers
Ears are low-set

Other:
Micrognathia (small jaw)
Congenital heart disease
Omphalocelegocele
Myelomeningocele

Death ~1yr

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70
Q

AUTO trisomies:

Patau Syndrome

A

Trisomy 13

Signs: Mid Line defects
Cutis aplasia
Severe intellectual disability
Rocker-bottom feet
Microphthalmia
Microcephaly
Cleft lip/palate
Holoprosencephaly
Polycystic kidney disease
Omphalocele
Death ~1 yr

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71
Q

Trisomy Screening

A
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72
Q

Trisomies:
3
4
5
6

A

3 von Hippel-Lindau disease, renal cell carcinoma

4 ADPKD (PKD2), achondroplasia, Huntington disease

5 Cri-du-chat syndrome, familial adenomatous polyposis

6 Hemochromatosis (HFE)

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73
Q

Trisomies:
7
9
11
13

A

7 Williams syndrome, cystic fibrosis

9 Friedreich ataxia, tuberous sclerosis (TSC1)

11 Wilms tumor, β-globin gene defects (eg, sickle cell disease, β-thalassemia), MEN1

13 Patau syndrome, Wilson disease, retinoblastoma (RB1), BRCA2

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74
Q

Trisomies:
15
16
17
18

A

15 Prader-Willi syndrome, Angelman syndrome, Marfan syndrome

16 ADPKD (PKD1), α-globin gene defects (eg, α-thalassemia), tuberous sclerosis (TSC2)

17 Neurofibromatosis type 1, BRCA1, TP53 (Li-Fraumeni syndrome)

18 Edwards syndrome

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75
Q

Trisomies:
21
22
X

A

21 Down syndrome

22 Neurofibromatosis type 2, DiGeorge syndrome (22q11)

X Fragile X syndrome, X-linked agammaglobulinemia, Klinefelter syndrome (XXY)

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76
Q

Robertsonian translocation:
Usually involves 21, 22, 13, 14, & 15

Balanced vs. unbalanced

A

Balanced: no gain/loss of genetic material (no abnormal phenotype)

Unbalanced: missing/extra genes (abnormal phenotype i.e down/patau syndromes)

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77
Q

Cri-du-chat syndrome

A

Congenital deletion of the short arm of chromosome 5 (46XX or XY)

Signs:
Microencephaly
Mod-severe intellect disability
High-pitched crying
Epicanthal folds
Ventral Septal Defect

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78
Q

Williams Syndrome

A

Congenital microdeletion of the long arm of chromosome 7 (induces elastin gene)

Signs:
Elfin facies
Well-developed verbal skills
Intellectual disabilities
Hypercalcemia
Cardiovascular issues (supravalvular aortic
stenosis, renal artery stenosis)

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79
Q

Essential fatty acids are

A

Polyunsaturated & not made by the body

  • Linoleic acid (Omega 3) => Cardiprotective cardioprotective + antihyperlipidemic effects
  • Linoleic acid (Omega 6) => metabolized to arachidonic acid (leukotrienes/prostaglandins)
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80
Q

Fat-soluble vitamins
“DrAKE”

A

Absorption via the ileum
Patients can have deficiencies from malabsorption syndromes & steatorrhea (i.e. cystic fibrosis or celiacs), or mineral oil intake can cause fat-soluble vitamin deficiencies

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81
Q

List of water-soluble vitamins:
B1
B2
B3
B5
B6
B7
B9
B12
C

A

B1 (thiamine, TPP)
B2 (Riboflavin, FAD & FMN)
B3 (Niacin, NAD)
B5 (Pantothenic acid, CoA)
B6 (Pyridoxine, PLP)
B7 (Biotin)
B9 (Folate)
B12 (Cobalamin)
C (Ascorbic acid)

B-complex deficiencies usually cause: Dermatitis, Glossitis, & Diarrhea

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82
Q

Vitamin A

A

Includes Retinol, Retinol, & Retinoic acid

Functions:
Antioxidant
Retinal pigment
Differentiate epithelium to specialized tissue
Prevents squamous metaplasia

Deficiency:
Night-Blindness (nyctalopia)
Dry/scaly skin (xerosis cutis)
Dry eyes (xerophthalmia)
Bitot spots (foamy conjunctiva)
Immunosuppression

Excess:
Acute toxicity (nausea, vomiting, high intracranial pressure (vertigo/blurred vision)

Chronic toxicity (alopecia, dry skin, hepatic toxicity/enlargement, arthralgia, idiopathic intracranial hypertension)

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83
Q

A 7-year-old girl is brought to a clinic because of fatigue and weight loss. She immigrated from a developing country with her family 1 week ago. The family has had very poor access to food for the past 2 years. The child says she feels itchiness all the time. She is at the 5th percentile for body weight, 50th percentile for height. On examination, her abdomen is scaphoid. She has dry eyes, and further evaluation shows diminished lacrimal gland function.

A

Vitamin A deficiency

Is associated with night blindness, decreased immunity, and impaired differentiation of specialized epithelia such as that on the eye (causing xerophthalmia and Bitot spots).

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84
Q

Mary is a 32-year-old woman who presents with increased flatulence, bloating, and diarrhea while eating a regular diet, including grains, meats, and vegetables. A biopsy shows blunting of intestinal villi. What is the likely cause of her malabsorption?

Celiac disease

Crohn disease

Lactose intolerance

Pancreatic insufficiency

Ulcerative colitis

A

The correct answer is celiac disease (A). Malabsorption and blunting of intestinal villi are hallmarks of celiac disease, an autoimmune process in response to gliadin, a component of gluten. Crohn’s disease (B), lactose intolerance (C), pancreatic insufficiency (D), and ulcerative colitis (E) can present with similar symptoms but don’t have the hallmark blunting of intestinal villi that is seen in celiac disease.

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85
Q

Adam is a 4-day-old male infant who was born at home with the help of a midwife. The delivery was uneventful. He now presents to the emergency department with excessive bleeding around the umbilicus that has failed to heal. What vitamin deficiency should be suspected?

Vitamin B9

Vitamin B12

Vitamin C

Vitamin D

Vitamin K

A

The correct answer is vitamin K (E), which is essential for the γ-carboxylation of clotting factors II, VII, IX, and X. Newborns are given a shot of vitamin K after birth because deficiency is common. Deficiencies of vitamin B9 (A), B12 (B), C (C), and D (D) would not cause increased bleeding times in this infant.

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86
Q

James is a 27-year-old man who complains of abdominal pain, bloating, diarrhea, and increased flatulence with the consumption of milk. What stage of the absorptive process is disrupted?

Intraluminal digestion

Lymphatic transport of lipids

Secretion of regulatory substances

Terminal digestion

Transepithelial transport

A

The correct answer is terminal digestion (D). This patient is lactose intolerant and is deficient in the brush border enzyme lactase. The malabsorption in this case is an inability to digest the sugar lactose found in milk products. Intraluminal digestion (A) is not specific for lactose and wouldn’t cause this process. Lymphatic transport of lipids (B) is still intact in a patient with lactose intolerance, because the disruption is with digestion of sugar. Disrupting the secretion of regulatory substances (C) can be caused by diseases like pancreatic insufficiency or pernicious anemia. This patient’s symptoms coinciding with milk consumption points to a deficiency of lactase, which is found in the brush border and is not a secreted regulatory substance. The transepithelial transport system (E) is still intact for other food products, because the symptoms are only with milk ingestion.

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87
Q

A 10-year-old male is brought to the clinic because of chronic diarrhea and increased fatigue. The patient reports that his stools smell foul and float in the commode. He has no blood in his stool. Vital signs are normal. On physical examination, he appears pale and thin. His abdomen is mildly tender to palpation in all four quadrants. Laboratory studies reveal the following:

Hemoglobin: 9.0 g/dL
Mean corpuscular volume: 73 μm3
Platelet count: 212,000/mm3
Leukocyte count: 6,000/mm3
Ferritin: 15 ng/mL

A duodenal biopsy specimen reveals the findings pictured.

A. Ascending weakness

B. Frequent bloody stools

C. Hyperpigmented skin lesions

D. Painful, tender, erythematous nodules on the shins

E. Small clusters of fluid-filled papules and vesicles

A

E. Small clusters of fluid-filled papules and vesicles

Celiac disease, an autoimmune disorder with intolerance to gluten, presents with foul-smelling diarrhea, steatorrhea, weight loss, fatigue, and abdominal pain.
Celiac disease is associated with dermatitis herpetiformis, a skin disorder with clusters of pruritic, papular, and sometimes bullous lesions that often appear in a symmetric pattern.

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88
Q

A 46-year-old woman goes to the physician because of intermittent bloating, abdominal pain, diarrhea, and flatulence. The diarrhea is watery and never oily. The condition is often worse after meals, but sometimes eating presents no problems. The patient has not tried to identify any dietary triggers and follows a normal diet with no restrictions. There is no family history of gastrointestinal problems. Stool studies reveal an osmotic gap of 200 mOsm/kg.

Which of the following conditions is most likely causing this patient’s symptoms?

A. Crohn disease

B. Escherichia coli enteritis

C. Irritable bowel syndrome

D. Lactose intolerance

E. Peptic ulcer disease

A

D. Lactose intolerance

Physical indicators of lactose intolerance include intermittent postprandial diarrhea, bloating, flatulence, and abdominal pain; an elevated stool osmotic gap essentially confirms the diagnosis.

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89
Q

A 42-year-old man comes to the physician with intermittent right-upper-quadrant abdominal pain that occurs most often after meals. The patient’s body mass index is 34 kg/m2.

Which of the following is most likely associated with this patient’s pain?

Acinar cell hypersecretion

Cholecystokinin release

Decreased gastric pH

Excessive gastrin release

Increased indirect bilirubin

A

Cholecystokinin release

Patients with gallstones present with postprandial pain in the upper right quadrant.
Cholecystokinin stimulates gallbladder contraction and increases pain in patients with gallstones.

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90
Q

A 32-year-old woman comes to the clinic because of chronic abdominal pain, steatorrhea, weight loss, fatigue, and joint pain. Upper endoscopy and tissue biopsy of the small intestine are performed, and the results are shown. The physician tells the patient that the condition can be managed through dietary changes.

Which of the following is associated with this patient’s most likely condition?

Acute lymphoblastic leukemia

Colonic polyp

Diverticula

Herpes simplex virus type 1 infection

Selective IgA deficiency

A

Selective IgA deficiency

Celiac disease commonly presents with abdominal pain, steatorrhea, weight loss, fatigue, and bone and joint pain. Histologic changes typically include intraepithelial lymphocytes, enterocyte damage, and villous blunting, leading to malabsorption.
Celiac disease is associated with IgA deficiency.

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91
Q

In a genetically modified mouse, researchers deleted a gene that is only expressed on the plasma membrane of enterocytes. When tested, the mice were found to have elevated high-molecular-weight proteins and complex lipids in their stool.

Which of the following would be deficient as a result of the most likely gene deletion?

Amylase

Chymotrypsinogen

Enterokinase

Lipase

Pepsin

A

Enterokinase

Enterokinase (enteropeptidase) allows the activation of several digestive enzymes responsible for degrading proteins and complex lipids.

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92
Q

A 22-year-old woman comes to the clinic because of increasing shortness of breath, weakness, and fatigue. She has a history of heavy menstrual bleeding. Physical examination reveals hair loss, koilonychia, and pale mucous membranes. Laboratory studies show a hemoglobin concentration of 6 g/dL, a mean corpuscular hemoglobin concentration of 24 Hb/cell, a mean corpuscular volume of 65 fL, and an RBC distribution width of 17%.

What part of the gastrointestinal tract is responsible for absorbing the nutrient in which this patient is most likely deficient?

Duodenum

Gastric body

Gastric fundus

Ileum

Jejunum

A

Duodenum

Iron-deficiency anemia is characterized by shortness of breath, weakness, fatigue, pale mucous membranes, low mean corpuscular volume, and high RBC distribution due to reduced oxygen delivery to the body.
Iron is predominantly absorbed in the duodenum, and damage to the duodenal enterocytes can lead to malabsorption of iron and iron-deficiency anemia.

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93
Q

A 46-year-old woman comes to the clinic for foul-smelling and bulky stools that float on the surface of the toilet water. She has chronic epigastric pain that is worse after eating. Her diarrhea resolves when she abstains from eating. Her medical history is significant for chronic heavy alcohol use. Physical examination reveals temporal wasting and epigastric tenderness. Her fasting serum glucose is 148 mg/dL.

Which of the following additional findings is most likely in this patient?

Blood and pus in the stool

Decreased transit time

Elevated 72-hour fecal fat

Positive Clostridioides difficile polymerase chain reaction

Reduced stool osmotic gap

A

Elevated 72-hour fecal fat

Chronic pancreatitis commonly manifests as a malabsorptive diarrhea because the pancreas is no longer capable of secreting an adequate amount of amylase and lipase (which are responsible for the digestion of carbohydrates and lipids).
Consequently, fats remain undigested in the intestines, and fecal fat levels are elevated.

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94
Q

A 49-year-old man presents to the physician with a 3-month history of joint pain throughout the body. Recently, the patient also has experienced abdominal pain, greasy stools, and a 6-kg (13.2-lb) weight loss. Physical examination is normal. The physician obtains a biopsy specimen of the lamina propria of the small intestine, and the results are shown.

Which of the following is the cause of this man’s symptoms?

Celiac sprue

Crohn disease

Mucosa-associated lymphoid tissue tumour

Ulcerative colitis

Whipple disease

A

Whipple disease

Caused by infection with T. whipplei, Whipple disease manifests via weight loss, diarrhea, and arthralgias; in addition, histology reveals PAS-positive macrophages in the lamina propria of the small intestine.

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95
Q

Vitamin B1

A

Aka Thiamine (TPP)

Functions:
Cofactor for
- Branched-chain ketoacid dehydrogenase
-A-ketoglutarate dehydrogenase (TCA)
- Pyruvate dehydrogenase (Links glycolysis –> TCA)
- Transketolase (HMP-shunt)

Deficiency:
Impaired glucose breakdown (worse with glucose infusion)
&
Give patients with chronic alcohol abuse or malnutrition. Thiamine before dextrose to avoid Wernicke’s encephalopathy!!

Labs:
High RBC transketolase activity from the administration of B1

Chronic toxicity (alopecia, dry skin, hepatic toxicity/enlargement, arthralgia, idiopathic intracranial hypertension)

Conditions:
Wernicke encephalopathy
Korsakoff Syndrome
BeriBeri (wet/dry)

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96
Q

Wernicke encephalopathy
“CorONA beer”

A

Acute & reversible but life-threatening neurological condition

Signs:
Confusion
Ophthalmoplegia
Nystagmus
Ataxia

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97
Q

Korsakoff Syndrome

A

Amnestic disorder from chronic alcohol abuse

Signs:
Confabulation
Personality changes
Permanent memory loss

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98
Q

Wernike-Korsakoff syndrome

A

Damaged medial dorsal nucleus of the thalamus + mamillary bodies

Signs: COMBO
Confusion
Ophthalmoplegia
Nystagmus
Ataxia
Confabulation
Personality changes
Permanent memory loss

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99
Q

Wernickes vs Korsakoff “COAT RACK”

A
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100
Q

Wet vs Dry Ber1Ber1

A

Wet: Polyneuropathy + symmetrical muscular wasting

Dry: High-output cardiac failure (dilated cardiomyopathy) + edema

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101
Q

Vitamine B2

“B2= 2ATP”

A

Riboflavin

Functions:
Part of FAD & FMN as cofactors in redox reactions (succinate DH (TCA))

Deficiency:
Cheilosis

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102
Q

Cheilosis

“2 C’s of B2”

A

Vitamin B2 deficiency

Signs:
Inflamed & Scaling/fissured lips
Magenta tongue
Corneal vascularization

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103
Q

Vitamin B3

“BC3 =3ATP”

A

Niacin & Nicotinic acid

Functions:
Derived from Tryptophan (needs Vit B2 + B6 to be made)
Part of NAD/NADP in redox reactions & cofactors for dehydrogenases
Used to treat dyslipidemia

Deficiency:
Glossitis
Pellagra

Causes of deficiency;
Hartnup disease

Excess:
Facial flushing (prostaglandin induced)
Gout (hyperuricemia)
Hyperglycemia

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104
Q

Pellagra

3 D’s

A

Can be due to a vitamin B3 deficiency

Dementia
Dermatitis
Diarrhea

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105
Q

Hartnup disease

A

AUTO REC

Deficient in neutral AAs like tryptophan causing vitamin deficiencies like Vit B3 def

Rx High protein diet & B3 supplementation

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106
Q

Vitamin B5

A

Pantothenic acid

Function:
Part of coenzyme A (CoA cofactor for acyl-transferases) & fatty acid synthesis

Deficiency:
Dermatitis
Enteritis
Alopecia
Adrenal insufficiency (burning feet syndrome)
Distal paresthesias
Dysesthesia

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107
Q

Vitamin B6

A

Pyridoxine

Function:
Converted to PLP, a cofactor in transamination (ALT/AST), decarboxylation, & glycogen phosphorylase-type reactions

Synthesis requires;
Glutathione
Cystathionine
Heme
Niacin
Histamine
Neurotransmitters (Serotonin, Epi/NoreEPI, Dopamine, & GABA)

Deficiency:
Convulsions
Hyperirritability
Peripheral neuropathy (Isoniazid inducible (from TB Rx))
Sideroblastic anemia

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108
Q

Vitamin B7

A

Biotin

Function:
Cofactor for carboxylation enzymes

  • pyruvate carboxylase (gluconeogenesis, pyruvate –> OAA)
  • acetyl-CoA carboxylase(fatty acid synthesis,acetylCoA ->MalonylCoA)
  • propionyl CoA carboxylase
    (fatty acid oxidation, propionyl CoA->Methylmalonyl-CoA)

Deficiency:
Dermatitis
Enteritis
Alopecia

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109
Q

Vitamin B9

“Give vit B9 at 9months preggo”

A

Folate

Function:
Made into THF (tetrahydrofolic acid)
&
Important for nitrogenous base synthesis in DNA/RNA

Deficiency:
Macrocytic megaloblastic anemia with hypersegmented PMN cells
Glossitis
NO neurological symptoms (as opposed to Vit B12 def)
High homocysteine levels
Normal methylmalonic acid

Causes:
Chronic alcohol abuse
Pregnancy
Drugs (Methotrexate, Phenytoin, & Sulfonamides)

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110
Q

Vitamin B12

A

Cobalamin

Functions:
Cofactor for methionine synthase & methyl malonyl-CoA mutase
Important for DNA synthesis

Deficiency:
Macrocytic megaloblastic anemia with hyper-segmented PMN cells
Paresthesia
NEUROLOGICAL SYMPTOMS
High homocysteine & methylmalonic acid levels

Causes:
Malabsorption
- Alcohol abuse, bacterial overgrowth, prolonged antibiotic use, or diphyllobotherium latum (tapeworm)

Lack of intrinsic factors
- Gastric bypass or pernicious anemia

Absent terminal ileum
Drugs (metformin)
Vegans

111
Q

Vitamin C

A

Ascorbic acid

Functions:
Antioxidant
Facilitates ferritin absorption by reducing it to iron
Cofactor for hydroxylation of lysine & proline in collagen synthesis
Needed for Dopamine B-hydroxylase to make Norepinephrine

Deficiency:
Scurvy

Causes:
Tea & Toast diet (usually affects elderly)

Excess:
Nausea, vomiting, diarrhea
Fatigue
Calcium oxalate nephrolithiasis
Can worsen hemochromatosis or transfer related iron overloads

112
Q

Scurvy

A

Vitamin C deficiency

Signs:
Swollen/bleeding gums
Easy bruising
Petechiae
Hemarthrosis
Anemia
Poor wound healing
Perifollicular + subperiosteal hemorrhages
Cork-screw hair
Immuno suppression

113
Q

Vitamin D

A

D2 (Ergocalciferol) = Sun, fish, milk, & plants
D3 (Cholecalciferol) = Plants, fungi, & yeast

Stored in the liver as 25-OH D3
Activated in the kidney as 1,25-(OH)2 D3

Function:
Intestine Ca2+ absorption
Bone storage/reabsorption of Ca2+ (if serum Ca2+ is high)
Bone mineralization/sequestration of Ca2+ (if serum Ca2+ is low)

Regulation:
PTH
- Increases serum Ca (more intestine absorption, bone mineralization, & PCT reabsorption of Ca2+)

Deficiency:
Rickette (kids)
Osteomyalgia (adults)

114
Q

Ricketts vs Osteomyalgia

A

Both Vitamin D deficiency

Signs:
Rickettes –> Genu varum (Bow leg)

Osteomyalgia –> Bone pain/weakness

Both hypocalcemic tetany

Cause:
Malabsorption
Little sun exposure
Diet
Chronic liver or kidney disease

Risks:
dark skin & premature birth

115
Q

Vitamin E

A

Tocopherol, Tocotrienol

Functions:
Antioxidant (protects RBC & cell membranes from free radicals)

Deficiency:
Hemolytic anemia
Acanthocystocis
Muscle weakness
Demyelination (low proprioception + vibration sensation)
Ataxia
Similar neurological deficits to vit B12 deficiency but NO megaloblastic anemia

Excess:
Risk of enterocolitis in infants
High dose of vitamin E fucks with vitamin K synthesis & enhances the anticoagulant effects of Warfarin

116
Q

Vitamin K

“K is for Koagulation”

“breast fed infants Don’t Know about vitamins K & D”

A

Phytomenadione, phylloquinone, phytonadione, & menaquinone

Function:
Activated by epoxide reductase in the liver to be a cofactor for y-carboxylation of glutamic acid residues on clotting proteins (II
, VII, IX, X, C, & S

Deficiency:
Neonatal hemorrhage with high PT & aPTT

117
Q

Zinc

A

Function:
Is essential for enzymes like transcription factor motifs

Deficiency:
Delayed wound healing
Suppressed immunity
Male hypogonadism
Less adult hair
Dysgensia (tongue)
Anosmia

Associated Conditions:
Acrodermatitis enteropathica (defective zinc absorption in intestines)

Pre-disposed to alcoholic cirrhosis

118
Q

Protein-energy malnutrition:

Kwashiorkor (MEALS)

Marasmus

A

Kwashiorkor:
Malnutrition
Edema
Anemia
Liver (fatty)
Skin lesions (hyperkeratosis/depigmentation)

Marasmus:
NO edema
Deficient calories
Sufficient nutrients
Muscle wasting

119
Q

Ethanol metabolism

A

High NADH/NAD ratio from ethanol metabolism:
- Inhibits TCA

  • Increases Ketogenesis, ketoacidosis, Hepatosteatosis, & lipogenesis

-Fasting glycemia (inhibited gluconeogenesis cause OOA goes to malate)

-

120
Q

Glycolysis

Rate-determining enzymes

Regulators

A

RLE:
Phosphofructokinase-1 (PFK-1)

Regulators:
AMP ⊕, fructose-2,6-bisphosphate ⊕
ATP ⊝, citrate ⊝

121
Q

Gluconeogenesis

Rate-determining enzymes

Regulators

A

RLE:
Fructose-1,6-bisphosphatase 1

Regulators:
AMP ⊝, fructose-2,6-bisphosphate ⊝
TCA cycle Isocitrate dehydrogenase ADP ⊕
ATP ⊝, NADH ⊝

122
Q

Glycogenesis

Rate-determining enzymes

Regulators

A

RLE:
Glycogen synthase Glucose-6-phosphate ⊕

Regulators:
insulin ⊕, cortisol ⊕
Epinephrine ⊝, glucagon ⊝

123
Q

Glycogenolysis

Rate-determining enzymes

Regulators

A

RLE:
Glycogen phosphorylase

Regulators:
Epinephrine ⊕, glucagon ⊕, AMP ⊕
Glucose-6-phosphate ⊝, insulin ⊝, ATP ⊝

124
Q

HMP shunt

Rate-determining enzymes

Regulators

A

RLE:
Glucose-6-phosphate dehydrogenase (G6PD)

Regulators:
NADP+ ⊕
NADPH ⊝

125
Q

De novo pyrimidine
synthesis

Rate-determining enzymes

Regulators

A

RLE:
Carbamoyl phosphate synthetase II

Regulators:
ATP ⊕, PRPP ⊕
UTP ⊝

126
Q

De novo purine
synthesis

Rate-determining enzymes

Regulators

A

RLE:
Glutamine-phosphoribosylpyrophosphate
(PRPP) amidotransferase

Regulators:
AMP ⊝, inosine monophosphate (IMP) ⊝,
GMP ⊝

127
Q

Urea cycle

Rate-determining enzymes

Regulators

A

RLE:
Carbamoyl phosphate synthetase I

Regulator:
N-acetylglutamate ⊕

128
Q

Fatty acid synthesis

Rate-determining enzymes

Regulators

A

RLE:
Acetyl-CoA carboxylase (ACC)

Regulators:
Insulin ⊕, citrate ⊕
Glucagon ⊝, palmitoyl-CoA ⊝

129
Q

Ketogenesis

Rate-determining enzymes

A

RLE:
HMG-CoA synthase

130
Q

Cholesterol synthesis

Rate-determining enzymes

Regulators

A

RLE:
HMG-CoA reductase

Regulators:
Insulin ⊕, thyroxine ⊕, estrogen ⊕
Glucagon ⊝, cholesterol ⊝

131
Q

Metabolism sites:

Mitochondria

A

Fatty acid oxidation (β-oxidation)
Acetyl-CoA production
TCA cycle, oxidative phosphorylation
Ketogenesis

132
Q

Metabolism sites:

Cytoplasm

A

Glycolysis
HMP shunt
Synthesis of cholesterol (SER)
Proteins (ribosomes, RER)
Fatty acids and nucleotides.

133
Q

Metabolism sites:

Cytoplasm & Mitochondria

“Hugs take two (both)”

A

Heme synthesis
Urea cycle
Gluconeogenesis

134
Q

Summary of metabolic pathways

A
135
Q

Key enzymes in lipid transport:

Cholesteryl ester transfer protein

Hepatic lipase

Hormone-sensitive lipase

Lecithin-cholesterol acyltransferase

Lipoprotein lipase

Pancreatic lipase

PCSK9

A

Cholesteryl ester transfer protein: Mediates transfer of cholesteryl esters to other lipoprotein particles.

Hepatic lipase Degrades TGs remaining in IDL and chylomicron remnants.

Hormone-sensitive lipase
Degrades TGs stored in adipocytes. Promotes gluconeogenesis by releasing glycerol.

Lecithin-cholesterol acyltransferase
Catalyzes esterification of 2⁄3 of plasma cholesterol (ie, required for HDL maturation).

Lipoprotein lipase Degrades TGs in circulating chylomicrons.

Pancreatic lipase Degrades dietary TGs in small intestine.

PCSK9 Degrades LDL receptor   serum LDL. Inhibition   LDL receptor recycling   serum LDL.

136
Q

MEN 1 (autosomal dominant MEN1 mutation)

MEN 2B (autosomal dominant RET mutation)

MEN 2A (autosomal dominant RET mutation)

A

Pancreatic, pituitary, parathyroid tumors

Thyroid tumors, pheochromocytoma,
ganglioneuromatosis, Marfanoid habitus

Thyroid and parathyroid tumors, pheochromocytoma

137
Q

Bronze skin
Orthostatic hypotension
Fatigue,
Weakness
Muscle aches
Weight loss
GI disturbances

A

Chronic 1° adrenal insufficiency (Addison disease) HIGH ACTH & α-MSH

138
Q

Shock, altered mental status, vomiting, abdominal pain,
weakness, fatigue

A

Acute adrenal insufficiency (adrenal crisis)

139
Q

Metabolic acidosis & compensatory respiration:
Deep, labored breathing/hyperventilation

A

Diabetic ketoacidosis (Kussmaul respirations)

140
Q

Jaundice, palpable distended non-tender gallbladder

A

Courvoisier sign (distal malignant obstruction of biliary
tree)

141
Q

Arthralgias, adenopathy, cardiac and neurological
symptoms, diarrhea

A

Whipple disease (Tropheryma whipplei)

142
Q

Severe jaundice in neonate

A

Crigler-Najjar syndrome (congenital unconjugated
hyperbilirubinemia)

143
Q

Golden brown rings around peripheral cornea
&
Low serum ceruloplasmin

A

Wilson disease (Kayser-Fleischer rings due to copper
accumulation

144
Q

Female, fat, fertile, forty

A

Cholelithiasis (gallstones)

145
Q

Painless jaundice with enlarged gallbladder

A

Cancer of the pancreatic head obstructing bile duct

146
Q

Bluish line on gingiva

A

Burton line (lead poisoning)

147
Q

Short stature, café-au-lait spots, thumb/radial defects,
 incidence of tumors/leukemia, aplastic anemia

A

Fanconi anemia (genetic loss of DNA crosslink repair;
often progresses to AML)

148
Q

Sudden swollen/painful big toe joint, tophi

A

Gout/podagra (hyperuricemia)

149
Q

Swollen, hard, painful finger joints in an elderly
individual, pain worse with activity

A

Osteoarthritis (osteophytes on PIP [Bouchard nodes], DIP
[Heberden nodes])

150
Q

Bone pain, bone enlargement, arthritis

A

Osteitis deformans (Paget disease of bone,  osteoblastic
and osteoclastic activity)

151
Q

Urethritis, conjunctivitis, arthritis in a male

A

Reactive arthritis associated with HLA-B27

152
Q

Cervical lymphadenopathy, desquamating rash, coronary
aneurysms, red conjunctivae and tongue, hand-foot
changes

A

Kawasaki disease (mucocutaneous lymph node syndrome,
treat with IVIG and aspirin)

152
Q

Kawasaki disease (mucocutaneous lymph node syndrome,
treat with IVIG and aspirin)

A

Cervical lymphadenopathy, desquamating rash, coronary
aneurysms, red conjunctivae and tongue, hand-foot
changes

153
Q

Resting tremor, rigidity, akinesia, postural instability,
shuffling gait, micrographia
&
Depigmentation of neurons in substantia nigra

A

Parkinson disease (loss of dopaminergic neurons in
substantia nigra pars compacta)

154
Q

Chorea, dementia, caudate degeneration

A

Huntington disease (autosomal dominant CAG repeat
expansion)

155
Q

Rapidly progressive limb weakness that ascends following
GI/upper respiratory infection

A

Guillain-Barré syndrome (acute inflammatory
demyelinating polyneuropathy)

156
Q

Renal cell carcinoma (bilateral), hemangioblastomas,
angiomatosis, pheochromocytoma

A

von Hippel-Lindau disease (deletion of VHL gene on
chromosome 3p)

157
Q

Staggering gait, frequent falls, nystagmus, hammer toes,
diabetes mellitus, hypertrophic cardiomyopathy

A

Friedreich ataxia

158
Q

Ptosis, miosis, anhidrosis

A

Horner syndrome (sympathetic chain lesion

159
Q

Polyuria, renal tubular acidosis type II, growth retardation,
electrolyte imbalances, hypophosphatemic rickets

A

Fanconi syndrome (multiple combined dysfunction of the
proximal convoluted tubule

160
Q

Periorbital and/or peripheral edema, proteinuria (> 3.5g/
day), hypoalbuminemia, hypercholesterolemia

A

Nephrotic syndrome

161
Q

Hereditary nephritis, sensorineural hearing loss,
retinopathy, lens dislocation

A

Alport syndrome (mutation in type IV collagen)

162
Q

Beckwith-Wiedemann syndrome (WT2 mutation)

A

Wilms tumor, macroglossia, organomegaly,
hemihyperplasia, omphalocele

163
Q

Streak ovaries, congenital heart disease, horseshoe kidney,
cystic hygroma, short stature, webbed neck, lymphedema

A

Turner syndrome (45,XO)

164
Q

Colonies of mucoid Pseudomonas in lungs

A

Cystic fibrosis (autosomal recessive mutation in CFTR
gene fat-soluble vitamin deficiency and mucous plugs)

165
Q

high AFP in amniotic fluid/maternal serum

A

Down syndrome, Edwards syndrome

166
Q

high β-hCG, low PAPP-A on first trimester screening

A

Down syndrome

167
Q

High serum homocysteine, high mehtylmalonic acid, low folate

A

Vitamin B12 deficiency

168
Q

low T cells, PTH, & Ca2+, absent thymic shadow on CXR

A

Thymic aplasia (DiGeorge syndrome, velocardiofacial
syndrome)

169
Q

Large granules in phagocytes, immunodeficiency

A

Chédiak-Higashi disease (congenital failure of
phagolysosome formation)

170
Q

Recurrent infections, eczema, thrombocytopenia

A

Wiskott-Aldrich syndrome

171
Q

Hypertension, hypokalemia, metabolic alkalosis

A

1° hyperaldosteronism (eg, Conn syndrome)

172
Q

Anti-transglutaminase/anti-gliadin/anti-endomysial
antibodies

A

Celiac disease (diarrhea, weight loss

173
Q

Narrowing of bowel lumen on barium x-ray

A

“String sign” (Crohn disease

174
Q

“Lead pipe” appearance of colon on abdominal imaging

A

Ulcerative colitis (loss of haustra)

175
Q

Thousands of polyps on colonoscopy

A

Familial adenomatous polyposis (autosomal dominant,
mutation of APC gene)

176
Q

Eosinophilic cytoplasmic inclusion in liver cell

A

Mallory body (alcoholic liver disease)

177
Q

Triglyceride accumulation in liver cell vacuoles

A

Fatty liver disease (alcoholic or metabolic syndrome)

178
Q

“Nutmeg” appearance of li

A

Chronic passive congestion of liver due to right heart
failure or Budd-Chiari syndrome

179
Q

Hypersegmented neutrophils

A

Megaloblastic anemia (B12 deficiency: neurologic
symptoms; folate deficiency: no neurologic symptoms)

180
Q

Basophilic nuclear remnants in RBCs

A

Howell-Jolly bodies (due to splenectomy or nonfunctional
spleen

181
Q

Basophilic stippling of RBCs

A

sideroblastic anemia

182
Q

Hypochromic, microcytic anemia

A

Iron deficiency anemia, lead poisoning, thalassemia (fetal
hemoglobin sometimes present

183
Q

“Hair on end” (“crew cut”) appearance on x-ray

A

β-thalassemia, sickle cell disease (marrow expansion

184
Q

Anti-GpIIb/IIIa antibodies

A

Immune thrombocytopenia

185
Q

Needle-shaped, ⊝ birefringent crystals

A

Gout (monosodium urate crystals

186
Q

high uric acid levels

A

Gout, Lesch-Nyhan syndrome, tumor lysis syndrome,
loop and thiazide diuretics

187
Q

“Bamboo spine” on x-ray

A

Ankylosing spondylitis (chronic inflammatory arthritis:
HLA-B27)

188
Q

Protein aggregates in neurons from hyperphosphorylation
of tau protein

A

Neurofibrillary tangles (Alzheimer disease) and Pick
bodies (Pick disease)

189
Q

Silver-staining spherical aggregation of tau proteins in
neurons

A

Pick bodies (frontotemporal dementia: progressive
dementia, changes in personality)

190
Q

“Waxy” casts with very low urine flow

A

Chronic end-stage renal disease

191
Q

WBC casts in urine

A

Acute pyelonephritis, transplant rejection,
tubulointerstitial inflammation

192
Q

RBC casts in urine

A

Glomerulonephritis

193
Q

hCG elevated

A

Multiple gestations, hydatidiform moles,
choriocarcinomas, Down syndrome

194
Q

Disease occurs in both males and females, inherited
through females only

A

Mitochondrial inheritance

195
Q

Down syndrome, fragile X syndrome

A

Intellectual disability

196
Q

Folate (pregnant women are at high risk; body stores only
3- to 4-month supply; prevents neural tube defects

A

Vitamin deficiency (USA)

197
Q

Gaucher disease

A

Lysosomal storage disease

198
Q

Diabetes mellitus type 1, SLE, Graves disease, Hashimoto
thyroiditis (also associated with HLA-DR5), Addison
disease

A

HLA-DR3

199
Q

Diabetes mellitus type 1, rheumatoid arthritis, Addison
disease

A

HLA-DR4

200
Q

Renal artery stenosis, chronic kidney disease (eg,
polycystic kidney disease, diabetic nephropathy),
hyperaldosteronism

A

Hypertension, 2°

201
Q

Marfan syndrome (idiopathic cystic medial degeneration)

A

Aortic aneurysm, thoracic

202
Q

Pituitary adenoma (usually benign tumor)

A

Hypopituitarism

203
Q

Thyroid dysgenesis/dyshormonogenesis, iodine deficiency

A

Congenital hypothyroidism (cretinism)

204
Q

Papillary carcinoma (childhood irradiation)

A

Thyroid cancer

205
Q

ƒ Iatrogenic (from corticosteroid therapy)
ƒ Adrenocortical adenoma (secretes excess cortisol)
ƒ ACTH-secreting pituitary adenoma (Cushing disease)
ƒ Paraneoplastic (due to ACTH secretion by tumors)
Moon face buffalo hump

A

Cushing syndrome

206
Q

Hypocalcemia of chronic kidney disease

A

2° hyperparathyroidism

207
Q

Adenomas, hyperplasia, carcinoma

A

1° hyperparathyroidism

208
Q

Accidental excision during thyroidectomy

A

Hypoparathyroidism

209
Q

Adrenal hyperplasia or adenoma

A

1° hyperaldosteronism

210
Q

Zollinger-Ellison syndrome (gastrinoma of duodenum or
pancreas), associated with MEN1

A

Refractory peptic ulcers and high gastrin levels

211
Q

Cushing ulcer ( intracranial pressure stimulates vagal
gastric H+ secretion)

A

Acute gastric ulcer associated with CNS injury

212
Q

Gilbert syndrome (benign congenital unconjugated
hyperbilirubinemia

A

Hereditary harmless jaundice

213
Q

Wilson disease

A

Hereditary ATP7B mutation (copper buildup in liver,
brain, cornea, kidneys

214
Q

Hemochromatosis

A

Multiple blood transfusions or hereditary HFE mutation
(can result in heart failure, “bronze diabetes,” and  risk
of hepatocellular carcinoma)

215
Q

Pancreatitis (acute

A

Gallstones, alcohol

216
Q

Pancreatitis (chronic)

A

Alcohol (adults), cystic fibrosis (kids

217
Q

Iron deficiency

A

Microcytic anemia

218
Q

Sickle cell disease (hemoglobin S)

A

Autosplenectomy (fibrosis and shrinkage)

219
Q

Turner syndrome (45,XO or 45,XO/46,XX mosaic)

A

1° amenorrhea

220
Q

Winters formula

A
221
Q

Henderson-Hasselbalch equation (for
extracellular pH)

A
222
Q

Anion gap

A
223
Q

AUTO REC
Mutated MTP gene
No chylomicrons, VLDL, LDL in blood
Def ApoB100/48

Severe fat malabsorption
Fail to thrive
Retinitis pigmentosa
Vitamin E def
Progressive Ataxia
Acanthocytosis

A

Abetalipoproteinemia

224
Q

Heat intolerance
Weight loss
Palpitations

A

Hyperthyroidism

225
Q

Cold intolerance
Weight gain
Brittle hair

A

Hyperthyroidism

226
Q

AUTO REC
DEF lipoprotein lipase or ApoC
High chylomicrons, TG, & cholesterol in blood

Pancreatitis
Hepatosplenomegaly
eruptive/pruritic xanthomas

A

I-Hyper chylomicronemia

227
Q

AUTO DOM
Absent/Def LDLR or ApoB100
High IIa: LDL & cholesterol & IIb LDL, Cholesterol, & VLDL in blood

Atherosclerosis
Tendon xanthoma
Corneal arcus

A

II Hypercholesteremia

228
Q

AUTO REC
Def ApoE
High chylomicrons, VLDL in blood
Premature atherosclerosis
tuberoeruptive/palmar xanthomas

A

III Dysbetalipoproteinemia

229
Q

AUTO DOM
Too much hepaiv VLDL with high VLDL & TG levels in the blood

Acute pancreatitis

A

III Hypertriglyceridemia

230
Q

X-linked REC
Peripheral neuropathy
Preg renal failure
Def a-galactosidase
Build up of ceremide trihexoside

A

Fabry

231
Q

Developmental delay
Corneal clouding
AUTO REC
Hepatosplenomegaly
Def A-L IDURONIDASE
Build up of heparan & dermatan sulfate

A

Hurlers

232
Q

Aggression
Milder than hurlers
X-linked REC
Def Iduronate 2 sulfatase
Build up of heparan & dermatan sulfate

A

Hunters

233
Q

No LCFA transport into the mitochondria
Weakness
Hypotonia
Hypoketotic
Hypoglycemia
Dilated cardiomyopathy

A

Systemic primary carnitine def

234
Q

Accumulation of fatty acyl carnitine in blood
Hypoketotic
Hypolgycemia
Hyperammonia
Vomit
Lethargy
Seizures
Coma
Liver dysfunction

A

Medium Chain Acetyl-CoA Dehydrogenase def

235
Q

AUTO REC
Hepatomegaly
Foam cells
def sphingomyelinase
build up of sphingomyelin
cherry red spot on macula

A

Nieman picks

236
Q

Hepatosplenomegaly
Osteoporosis
pancytopenia
Def glucocerebrosidase
Build up of Glucocerebrosidase
AUTO REC

A

Gaucher

237
Q

AUTO REC
Peripheral neuropathy
Optic atrophy
def Glucocerebroside
Build up of Glucocerebroside

A

Krabbe

238
Q

Central + peripheral demyelination
Ataxia
Dementia
Def Arylsulfatase A
Build up of cerebroside sulfate
AUTO REC

A

Metachromatic Leukodystophy

239
Q

Homogentisate oxidase def
Ochronosis (blue/black ears, hands, eyes)
urine turns black when exposed to air

A

Alkaptonuria

240
Q

Skeletal muscle phosphorylase def
Chronic exercise intolerance
Myalgia/cramps
Myoglobinuria

A

McArdles

241
Q

Debrancing enzyme def (glu6-phosphatase)
infants with hypoglycemia + hepatomegaly

A

Cori

242
Q

Lysosomal a 1,4-glucosidase def
Myopathy
Infantile hypertrophic cardiomyopathy

A

Pompe

243
Q

AUTO REC
Def Hexosaminidase A
Build up of Ganglioside
Cherry red macula spot
Developmental delay
Neurodegen
Lysosomes with onion skin

A

Tay Sachs

244
Q

Hemorrhagic new born disease with
high PT & aPTT

A

Vit K def

245
Q

HGPRT def
X-linked RED
Gout
Self-Mutilation
Intellectual disability

A

Lesh-Nyhan Syndrome

246
Q

AUTO REC
Arachnodactyly
Down/out lens dislocation
Pectus deformity

A

Homocystinuria

247
Q

CFTR gene defect on X7
Phe deletion
Meconium ileus (neonates)
Recurrent pulmonary infection
Nasal polyps
Pancreatic insufficiency
Infertility

A

Cystic fibrosis

248
Q

Gs protein activating mutation
Unilateral cafe du lait spots + ragged edges
Polyostotic fibrous displagia (bone replaced by collagen)

A

McCune-Albright syndrome

249
Q

Def vitamin B1
Dilated cardiomyopathy/high out put cardiac failure
Edema
Alcoholism or malnutrition

A

Ber1Ber1

250
Q

Burning feet syndrome

A

Vit B5 def

251
Q

Vit B3 def

A

pellagra (dermatitis, dementia, diarrha)

252
Q

Catecholamine Met

A
253
Q

Adrenals & hormones

A
254
Q

FA MET

A
255
Q

FEDVSFASTED

A
256
Q

HH equation

A
257
Q

ETC

A
258
Q

Chylomicron transport

A
259
Q

Anterior pituitary hormone release pathway

A
260
Q

Calcium reg

A
261
Q

Cholesterol hormone synthesis enzymes

A
262
Q

Pituitary hormone pathway

A
263
Q

Carnitine shuttle

A
264
Q

Steroid hormone pathways

A
265
Q

Pyruvate MET

A
266
Q

Apolipoproteins

A
267
Q

VLDL

A
268
Q

Pancreas cells

A
269
Q

Endocrine hormone signalling pathways

A
270
Q

Adrenal steroid hormone synthesis pathway

A
271
Q

G6P path

A
272
Q

Cholesterol hormone synthesis enzymes

A
273
Q

ADH

A

Biochem NBME (1 decks)

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