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DIT FACTS > BIOCHEM > Flashcards

BIOCHEM Flashcards

1
Q

How is hnRNA processed before it leaves the nucleus?

A

5’ cap
Poly A tail
Splicing out of introns
mRNA leaves nucleus

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2
Q

How does hexokinase differ from glucokinase?

A

Hexokinase: everywhere. It is not induced by insulin. It has a low Km and a low Vmax.
Glucokinase is only in the pancreas (beta cells) and liver. It IS induced by insulin. It has a high Km and a low Vmax.

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3
Q

What is the result of a glycolytic enzyme deficiency?

A

RBC hemolysis

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4
Q

What is the result of a deficiency in pyruvate dehydrogenase?

A

Neurological effects

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5
Q

Rate limiting enzyme of hexose monophosphate pathway

A

Glucose 6 phosphate dehydrogenase

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6
Q

Rate limiting enzyme of fatty acid synthesis

A

Acetyl CoA carboxylase

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7
Q

Rate limiting enzyme of beta oxidation of fatty acids

A

carnitine acyltransferase

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8
Q

Rate limiting enzyme of ketone body synthesis

A

HMG CoA synthase

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9
Q

Rate limiting enzyme of cholesterol synthesis

A

HMG CoA reductase

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10
Q

Where does fatty acid degradation take place?

A

Mitochondria

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11
Q

Where does fatty acid synthesis take place?

A

Cytoplasm

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12
Q

Where does glycolysis take place?

A

Cytoplasm

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13
Q

Where does the TCA cycle take place?

A

Mitochondria

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14
Q

Where is the ETC/oxidative phosphorylation?

A

Mitochondria

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15
Q

Where does gluconeogenesis take place?

A

Mitochondria AND cytoplasm

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16
Q

Enzyme deficient in Fructose intolerance

A

Aldolase B

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17
Q

Enzyme deficient in Essential fructosuria

A

Frucokinase

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18
Q

Enzyme deficient in Classic galactosemia

A

Galactose-1-phosphate uridyltransferase

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19
Q

Tryptophan is the derivative of

A

Niacin (becomes NAD+/NADP+) –requires B6

Serotonin (becomes melatonin)–requires BH4

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20
Q

Histidine is derivative of

A

Histamine. This conversion requires B6.

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21
Q

Glycine is derivative of

A

Porphyrin (which gets broken down into heme.) This requires B6.

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22
Q

Arginine is derivative of (3)

A

Creatine
Urea
Nitric oxide

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23
Q

Glutamate is derivative of

A

GABA (requires B6)

Glutathione

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24
Q

BH4 is required for which 3 conversions?

A

Phenylalanine –> Tyrosine
Tyrosine –> Dopa
Tryptophan –> Serotonin

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25
Q

Rate limiting enzyme in heme synthesis

A

Conversion of glycine and succinyl CoA to delta-Aminolevulinate acid

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26
Q

Carbamoyl phosphate synthetase I

A

Involved in urea cycle which takes place in mitochondria.

Gets nitrogen from ammonium

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27
Q

Carbamoyl phosphate synthetase II

A

Involved in pyrimidine synthesis which takes place in the cytosol.
Gets nitrogen from glutamine.

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28
Q

Most common urea cycle disorder and its main characteristics

A

ORNITHINE TRANSCARBAMOYLASE DEFICIENCY.
X-linked recessive**
Interferes with body’s ability to eliminate ammonia
Excess carbamoyl phosphate is converted to orotic acid (part of the pyrimidine synthesis pathway.)
Increased orotic acid in blood and urine
Decreased BUN (because urea cycle is not occurring)
Symptoms of hyperammonemia (hepatoencephalopathy).

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29
Q

Enzyme that converts phenylalanine to tyrosine

A

Phenylalanine hydroxylase

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30
Q

Enzyme that converts tyrosine to dopa

A

Tyrosine hydroxylase

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31
Q

Enzyme that converts dopa to dopamine

A

Dopa decarboxylase

*this requires B6

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32
Q

Enzyme deficiency that leads to mental retardation, growth retardation, seizures, fair skin, eczema, and a musty body odor

A

Phenylalanine hydroxlyase or tetrahydrobiopterin cofactor.
This autosomal recessive d/o of AROMATIC amino acid metabolism leads to excess phenylketones in the urine (phenylacetate, phenyllactate, and phenylpyruvate)

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33
Q

Enzyme deficient in patient with dark connective tissue, debilitating arthralgias, brown pigmented sclera, and urine that turns black on prolonged exposure to air

A

This is alcaptonuria. It is the deficiency of homogentistic acid oxidase in the degradative pathway of tyrosine to fumarate, causing homogentisate to accumulate.

Its autosomal recessive.

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34
Q

3 possibily causes of homocystinuria

A

Cystathionine synthase deficiency
Decreased affinity of cystathionine synthase for pyridoxal phosphate
Homocysteine methyltransferase deficiency

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35
Q

2 diseases that can cause lens subluxation

A

Marfans

Homocystinuria

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36
Q

Findings in homocystinuria

A 
Increased homocystine in urine
MR
Osteoporosis
Tall stature
Kyphosis
Lens subluxation (downward, inward)
Atherosclerosis ( -- > stroke, MI)
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37
Q

Enyme that converts homocysteine to methionine and cofactor

A

Homocysteine methyltransferase

B12

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38
Q

Enzyme that converts homocysteine to cystathionine and cofactor

A

Cystathionine synthase

B6

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39
Q

Cystinuria defect

A

Renal tubular amino acid transporter for COLA –cysteine, ornithine, lysine, and arginine. It is found in the PCT of the kidneys. This is autosomal recessive and can lead to renal staghorn calculi!

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40
Q

Enzyme deficient in Maple Syrup Urine Disease

A

alpha-ketoacid dehydrogenase (B1)
Causes increased leucine, isoleucine, valine in the urine –particularly leucine.
Autosomal recessive.

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41
Q

Hartnup disease is characterized by what defect

A

Neutral amino acid transporter on renal and ntestinal epithelial cells. Thus, we can’t use tryptophan to make niacin (B3), leading to PELLAGRA (dermatitis, dementia, diarrhea, death.)

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42
Q

Rate limtiing enzyme of glycolysis

A

Phosphofructokinase

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43
Q

Rate limiting enzyme of gluconeogenesis

A

Fructose 1,6 bisphosphatase

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44
Q

Rate limiting enzyme of TCA cycle

A

Isocitrate dehydrogenase

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45
Q

Rate limiting enzyme of glycogen synthesis

A

Glycogen synthase

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46
Q

Rate limiting enzyme of glycogenolysis

A

Glycogen phosphorylase

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47
Q

Rate limiting step of purine synthesis

A

Glutamine PRPP aminotransferase

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48
Q

Rate limiting step in pyrimidine synthesis

A

CPS II

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49
Q

Sources of carbon in formation of purines

A

CO2
Glycine
Tetrahydrofolate

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50
Q

Sources of carbon in formation of pyrimidines

A

CO2

Aspartate

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51
Q

What accounts for + charge o histones

A

Lysine, arginine

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52
Q

what accounts for - charge of DNA

A

phosphate groups

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53
Q

Transition mutation

A

Mutation that substitutes a pyrimidine for a pyrimididine (or purine for purine)

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54
Q

Transversion mutation

A

Mutation that substitutes a purine for a pyrimidine or vice versa

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55
Q

Retardation, self-mutilation, aggression, hyperuricemia, gout, choreoathetosis – > which enzyme is deficient?

A

This is Lesch-Nyhan syndrome, which is the result of defective purine salvage due to absence of HGPRT. This enzyme should convert hypoxanthine –> IMP and guanine —> GMP. This causes excess uric acid production and de novo purine synthesis.
This d/o is X-linked recessive.

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56
Q

Adenosine deaminase deficiency pathogenesis

A

Excess ATP and dATP imbalances nucleotide pool via feedback inhibition of ribonucleotide reductase. This prevents DNA synthesis, thus decreasing lymphocyte count.

It is autosomal recessive.

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57
Q

Increased orotic acid in urine, megaloblastic anemia, failure to thrive, but NO hyperammonemia — > which enzyme is deficient?

A

This is OROTIC ACIDURIA.
Either orotate phosphoribosyl transferase and/or OMP decarboxylase is deficient, resulting in the inability to convert orotic acid to UMP (de novo pyrimidine synthesis pathway).

Its autosomal recessive. Give these patients uridine.

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58
Q

Role of DNA polymerase alpha

A

Replicates lagging strand

Synthesizes RNA primer

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59
Q

Role of DNA polymerase beta & delta

A

Repair DNA

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60
Q

Role of DNA polymerase gamma

A

Replicates mitochondrial DNA

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61
Q

Role of DNA polymerase delta

A

Replicates leading strand DNA

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62
Q

2 enzymes involved in hemoglobin synthesis that are inhibited by lead toxicity

A

Ferrochelatase
ALA dehydratase
Causes a microcytic hypochromic anemia with ringed sideroblasts (iron-laden macrophages in RBC precursors)

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63
Q

Alcoholic male presents with blistering lesions in sun-exposed areas, particularly the dorsum of the hands. He also has hypertrichosis and hyperpigmentation on the face.

  • Dx?
  • Enzyme deficient?
  • Accumulated substrate?
A

Porphyria cutanea tarda (most common porphyria)
Uroporphyrinogen decarboxylase is deficient
Buildup of uroporphyrin causing tea-colored urine

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64
Q

Patient presents with a rash around the eyes, mouth, nose, and anus.

  • Deficiency of?
  • Associated sx with this deficiency
A

Zinc deficiency
This is known as acrodermatitis enteropathica.
Zinc deficiency can also cause anorexia, diarrhea, growth retardation, depressed mental function, impaired night vision, and infertility.

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65
Q

To what main 2 molecules is iron bound in human cells?

A

Myoglobin and ferritin

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66
Q

To what main 2 molecules is iron bound in blood?

A

Hb

Transferrin

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67
Q

Cause of Burton’s lines in lead poisoning

A

Lead interferes with normal remodeling of cartilage due to the interruption of calcium and Vit D homeostasis

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68
Q

Cancer associated with arsenic

A

Basal and squamous cell CAs

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69
Q

Peeling of the fingertips – what do I have?

A

Either mercury poisoning or Kawasaki’s disease

It’s known as acrodynia.

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70
Q

Organs affected by excess cadmium

A

Bone –osteoporosis/osteomalacia
Kidney injury
Lungs–increased risk of lung cancer

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71
Q

Organs primarily affected by excess mercury

A

Kidneys

Brain

72
Q

What are 3 different mechanisms that cells employ to break down proteins?

A

Ubiquitin protein ligase
Lysosomes
Calcium-dependent enzymes

73
Q

Enzyme that catalyzes peptide bond formation during protein synthesis

A

Peptidyl transferase (ribozyme)

74
Q

2 major functions of Von Willebrand factor

A

Complexes with and stabilizes factor VIII (thus, a deficiency would cause increased PTT).
Platelet adhesion to vessel wall and other platelets (thus a deficiency causes increased bleeding time)

75
Q

How does biological form of Vit D exert its actions

A

Interacts directly with target cell DNA to selectively stimulate or repress gene expression

76
Q

How does Vit D help maintain adequate levels of plasma calcium

A

Increases calcium uptake in intestine via increased expression of calcium binding protein
Stimulates PTH-dependent reabsorption of calcium in distal tubules
Stimulates bone resorption when necessary, along with PTH

77
Q

4 steps in metabolism of vitamin D

A

Gut absorption (D2) or skin synthesis (D3)
Binding to plasma alpha1-globulin (D-binding protein) and transport to liver
Conversion to 25-hydroxycholecalciferol by 25-hydroxylase in LIVER
Conversion of 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol by a1-hydroxylase in kidney

78
Q

Precursor of Vitamin D3 in skin

A

7-dehydrocholesterol

79
Q

Which form of Vitamin D is preferred in supplementation?

A

D3 (cholecalciferol)

80
Q

How does Vit D deficiency cause clinical sx

A

Lack of vitamin d causes hypocalcemia–> increased PTH
Mobilization of calcium from bone, decreased renal calcium excretion, increased renal excretion of phosphate –>hypophosphatemia –>impairment of bone mineralization

81
Q

Basic derangement in rickets/osteomalacia

A

Excess in unmineralized bone matrix

82
Q

In what disease does Vitamin D toxicity result from excess macrophage generation of 25-hydroxy-vitamin D?

A

Sarcoiosis

83
Q

Principle role of Vitamin K

A

Post-translational modification of various clotting factors where it serves as a coenzyme in carboxylation of certain glutamic acid residues present in these proteins

84
Q

WHy are newborns particularly prone to Vitamin K deficiency and what prophylactic measures can be taken?

A

Newborns do not have microbes in gut to produce vitamin K and mother’s milk only provides 1/5th of what they need. It is recommended newborns receive a single IM dose of vitamin K at birth.

85
Q

3 Rx that cause Vitamin K deficiency with long-term use

A

Coumadin
Anticonvulsants
Abx (loss of gut bacteria)

86
Q

What characterizes Vit K toxicity?

A

Hemolytic anemia and jaundice in an infant

87
Q

Retinol esters are stored in liver until needed by body. How are they transported in teh body when needed?

A

Via plasma retinol-binding protein

88
Q

In what broad metabolic functions is Vitamin A necessary?

A

Vision
Growth
Reproduction (spermatogenesis, prevent fetal resorption)
Maintenance of epithelial cells (especially mucous-secreting)

89
Q

4 signs of Vitamin A deficiency

A

Night blindness
Xerophthalmia – > corneal ulceration, blindness
Keratomalacia (wrinkling, clouding of corena)
Bitot’s spots (dry, silver gray plaques on bulbar conjunctiva)

90
Q

5 signs of hypervitaminosis A

A 
H/A causing N/V, stupor
Skin -dry, pruritic
Liver-enlarged (possibly cirrhotic)
Bone and joint pain
Increased intracranial pressure --pseudotumor cerebri
91
Q

3 congenital malformations associated with Vitamin A deficiency during preganncy

A

Cleft lip
Cleft palate
Neural crest cell derived structures

92
Q

In which 2 patient populations is Vitamin A supplementation a bad idea?

A

Pregnancy

Smokers (increased risk of lung cancer)

93
Q

Main metabolic reaction Vitamin C is involved in

A

Hydroxylation of prolyl and lysyl residues of collagen

94
Q

Another name for vitamin E

A

alpha tocopherol

95
Q

Associated with Vitamin E deficiency

A

Spinocerebellar degeneration – > ataxia

Peripheral neuropathy, proximal muscle weakness

96
Q

Mutations in what gene results in AR hereditary Vit E deficiency

A

Alpha-tocopherol transfer gene protein

97
Q

Intracellular storage form of folic acid

A

N-methyl folate

98
Q

How much folate should sexually active woman of childbearing age take to prevent neural tube efects

A

0.4 mg of folic acid a day

4 grams if at high-risk for neural tube defects

99
Q

An excess of folate can cause what kind of deficiency?

A

B12 because this vitamin is used in making tetrahydrofolate

100
Q

B12 deficiency can cause a deficiency in what?

A

Folate

101
Q

In what 2 metabolic reactions is Vit B12 involved?

A 
Homocysteine & methyl THF -- > methionine and THF (required for SAM to function)
Methylmalonyl CoA (coenzyme A) --> succinyl CoA
102
Q

Where is B12 absorbed in GI tract?

A

Distal ileum

103
Q

Metabolic function of pyridoxal phosphate

A

Coenzyme for numerous enzymes including those of AA metabolism (transaminations and deaminations)

104
Q

Distinguish Vitamin B6 from Vitamin B2 (riboflavin) deficiencies.

A

Vitamin B6 deficiency has convulsions, hyperirritability, and peripheral neuropathy in addition to sx of Vitamin B2 deficiency (dermatitis, angular stomatitis and chelosis, glossitis)

105
Q

Thiamine is AKA

A

B1

106
Q

Pantothenic acid is AKA

A

B5

107
Q

Folic acid is AKA

A

B9

108
Q

Niacin is AKA

A

B3

109
Q

Riboflavin is AKA

A

B2

110
Q

Functionally active form of thiamine (B1)?

A

Thiamine pyrophosphate

111
Q

Pt presents with wrist drop and hyporeflexia. They eat a lot of polished rice. What vitamin are they deficient in?

A

This is dry beri-beri. Deficient in thiamine

112
Q

Characteristics of Wet Beri Beri

A

Peripheral vasodilation causing high output heart failure – > peripheral edema, cardiomegaly

113
Q

2 biologically active forms of B2 and role of these molecules

A

Riboflavin –> Flavin mononucleotide and flavin adenine denucleotide
Both are cofactors for redox reactions

114
Q

Sx associated iwth riboflavin deficiency

A

Dermatitis
Cheilosis/angular stomatitis
Glossitis

115
Q

5 nutrient deficiencies associated with cheilosis, glossitis, and stomatitis?

A 
Iron
Riboflavin
Niacin
Folate
B12
116
Q

Biologically active forms of niacin and role of these molecules

A

NAD+ and NADP+

Both are cofactors for redox reactions

117
Q

Why is pellagra seen in population that eats primarily corn?

A

Tryptophan can be metabolized to form niacin and corn is lacking in tryptophan.

118
Q

How is niacin effective in treating type IIb hyperlipoproteinemia?

A

Inhibits lipolysis in adipose tissue – > less circulating FFAs – > less fatty acids to liver – > less VLDL made – > less LDL produced

119
Q

Role of pantothenic acid in metabolism

A

B5 is a component of CoA which functions in transfer of acyl groups

120
Q

Metabolic role of biotin

A

Apoenzyme in carboxylation reactions (hint: buy a tin of CO2!)

121
Q

2 things that can cause biotin deficiency

A 
Glycoprotein avidin found in egg whites prevents absoprtion of biotin
Abx use (gut bacteria make our biotin for us)
122
Q

Vitamins used by pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase (there are 5)

A 
B1 (thiamine)
B2 (riboflavin)
B3 (niacin)
B5 (pantothenic acid)
Lipoic acid
123
Q

Characteristic sequence of promotor region and what a mutation in this sequence results in?

A
  • 25 TATA box (Hogness box)
  • 75 CAAT box

Mutation results in a decreased amount of transcribed gene.

124
Q

What does a mutation in Homeobox HOXD-13 lead to?

A

Synpolydactyly (extra fused digit between 3rd and 4th fingers)

125
Q

What are the homeobox (HOX) genes?

A

Blueprint for skeletal morphology

Code for transcription regulators

126
Q

What are nuclear localization signals?

A

AA sequences (4-8 AAs) rich in lysine, arginine, and proline
Essential component of proteins bound for or residing in the nucleus, such as histones
Nuclear pores recognize these signals and transport the proteins into the nucleus via ATPase
A mutation in a single AA may prevent nuclear transport

127
Q

Molecules that provide the structural framework for DNA and nuclear envelope

A

Nuclear lamins

128
Q

Which cyclin-CDK complexes assist in progression from G1 –> S?

A

Cyclin D + CDK4 (activation of CDK4 allows for phosphorylation of Rb protein, allowing Rb to be released from transcription factor E2F. Now the cell is free to transcribe/synthesize components needed for progression through S phase)
Cycline E + CDK2

129
Q

Which tumor suppressor proteins prevent progression of cell into S phase

A

Rb

p53

130
Q

Which cyclin-CDK complexes assist in progression from G2 phase to M phase?

A

Cyclin A + CDK2

Cyclin B + CDK1

131
Q

I-cell disease deficiency and sx

A

Deficiency in mannose phosphorylation since there is no mannose-6-phosphate to target lysosomal proteins in the endoplasmic reticulum. Therefore, secretion is out of the cell vs. into lysosomes.
Most patients die by age 8.
They have corneal clouding, coarse facies, hepatosplenomegaly, skeletal abnormalities, restricted joint movement, and may or may not have mental retardation.

132
Q

2 cell types rich in smooth ER

A

Hepatocytes

Hormone-producing cells of adrenal cortex

133
Q

Vimentin is a structural component of what kind of tissue?

A 
Connective tissue (fibroblasts, leukocytes, endothelium)
It supports cellular membranes and keeps certain organelles fixed in cytoplasm.
134
Q

Desmin is an intermediate filament found in what kind of cells?

A

Muscle cells (smooth, skeletal, heart)

135
Q

Peripherin is an intermediate filament found in what kind of cells?

A

Neurons

136
Q

What intermediate filament is mutated in Progeria?

A

Progeria is super fast aging (like that benjamin button movie).
Its the mutation of nuclear lamins, which form the structural component of the nuclear envelope and DNA within.

137
Q

2 fundamental substances that make most things work inside cells

A

ATP

Ca2+

138
Q

Organelle responsible for breakdown of very long chain fatty acids and certain amino acids

A

Peroxisome

139
Q

Arachidonic acid products that increase bronchial tone

A

Leukotrienes

Thromboxane

140
Q

Arachidonic acid products that decrease bronchial tone

A

Prostacyclin

Prostaglandins

141
Q

Arachidonic acid product that increases platelet aggregation

A

Thromboxane

142
Q

Arachidonic acid product that increases uterine tone

A

Prostaglandin

143
Q

Arachidonic acid product that decreases platelet aggregation

A

Prostacyclin

144
Q

Arachidonic acid product that decreases uterine tone

A

Prostacyclin

145
Q

Arachidonic acid product that increases vascular tone

A

Thromboxane

146
Q

Arachidonic acid products that decrease vascular tone

A

Prostaglandin

Prostacyclin

147
Q

2 most abdunant substances in plasma membrane

A

Cholesterol

Phospholipid

148
Q

Protein involved in transporting an endocytosed vesicle from plasma membrane to endosome

A

Clathrin

149
Q

What defect do you suspect in a patient that suffers an MI prior to the age of 20?

A

Familial hypercholesterolemia (hyperlipidemia type IIa). Elevated LDL due to defective or absent LDL receptors. Severe atherosclerotic dz early in life and tendon xanthomas. This is an AD disease.

150
Q

4 classic findings in Osler Weber Rendu syndrome

A

This is an AD disorder of blood vessels. Its also known as Hereditary Hemorrhagic Telangiectasia. Generally these patients have telangiectasias, recurrent epistaxis, ski ndiscolorations, and arteriovenous malformations.

151
Q

Hormonal levels and chromosomal location of gene associated with Huntington’s disease

A

Decreased levels of both GABA and ACh

Gene located on chromosome 4

152
Q

ret gene

A

MEN 2A, 2B

153
Q

5 classic findings in Neurofibromatosis Type I

A

This is an AD disorder characterized by cafe au lait spots, neural tumors, Lisch nodules (pigmented iris hamartomas), skeletal d/o (like scoliosis) and optic nerve pathway gliomas.

On long arm of chromosome 17.

154
Q

2 classic findings in Neurofibromatosis Type 2

A

Bilateral acoustic schwannomas + juvenile cataracts

NF2 gene on chromosome 22

155
Q

Inheritance pattern of Tuberous Sclerosis

A

Incomplete penetrance, autosomal dominant

156
Q

Constitutive expression of which factors occur with deletions of VHL gene on chromosome 3?

A

This is Von Hippel Lindau disease. Deletions of the VHL gene (tumor suppressor) results in the constitutive expression of HIF (transcription factor) and activation of angiogenic growth factors.

157
Q

Trinucleotide repeat of Fragile X

A

CGG

158
Q

Trinucleotide repeat of Friedrich’s ataxia

A

GAA

159
Q

Trinucleotide repeat of Myotonic dystrophy

A

CTG

160
Q

Mnemonic for x-linked diseases

A

Fabrys Tale: Duke the Muscular Hunter Brutally Lysed the Albino Gopher without being aWAre it was a Fragile Hemophiliac!

161
Q

Most common lysosomal storage disease

A

Gaucher’s disease

162
Q

Only 2 x linked recessive lysosomal storage diseases

A

Fabrys
Hunters

Others are AR.

163
Q

Which 3 lysosomal storage diseases are associated iwth an early death (usually by age 3)?

A

Tay Sachs
Nieman Pick
Krabbe’s disease

164
Q

Which lysosomal storage diseases are particularly common among Ashkenazi Jews?

A

Tay Sachs
Niemann Pick
Gaucher

165
Q

Accumulation of ceramide trihexoside

A

Fabry’s disease –XR

Peripheral neuropathy of hands/feet
Angiokeratomas
Cardiovascular/renal disease

Deficient in alpha galctosidase A

166
Q

Macrophages that look like crumpled tissue paper

A

Gaucher’s disease – hepatosplenomegaly, aseptic necrosis of femur, bone crises, Gaucher’s cells

Deficient in glucocerebrosidase – > accumulaton of glucocerebroside

167
Q

4 clinical mx of sphingomyelinase deficiency

A

Niemann Pick disease – > progressive neurodegeneration, hepatosplenomegaly, cherry-red spot on macula, foam cells.

AR.

168
Q

Lysosomes with onion-skin

A

Tay-Sachs, a deficiency in Hexosaminidase A causing accumulation of GM2 ganglioside

Progressive neurodegeneration, developmental delay, cherry red spot on macula, NO hepatosplenomegaly * vs Niemann Pick

169
Q

Galactocerebrosidase deficiency

A

Krabbe’s disease – AR

Peripheral neuropathy, developmental delay, optic atrophy and globoid cells

170
Q

Deficiency of arylsulfatase A

A

Metachromatic leukodystrophy causing accumulation of cerebroside sulfate.

Central and peripheral demyelination with ataxia, dementia.

171
Q

Deficiency of alpha L-iduronidase

A

Hurlers syndrome – developmental delay, gargoylism, airway obstruction, corneal clouding, hepatosplenomegaly, bulging frontal bones

Accumulation of heparan and dermatan sulfate.
AR – nonsense mutation

172
Q

Deficiency of iduronate sulfatase

A

Mild Hurlers + aggressive behavior, NO corneal clouding.

Accumulation heparan and dermatan sulfate.
XR.

173
Q

Characteristic features of Prader Willi

A

Paternal allele is not expressed, maternal allele was inactivated.
Presents in infancy as hypotonia, poor feeding, almond hspaed eyes, downward turned mouth. Patient gets hyperphagia –> obesity, short stature, MR, behaviorr disorders (skin picking, OCD), and a hypogonadotrophic hypogonadism causing gential hypoplasia, osteoporosis, and delayed menarch.

174
Q

Characteristic features of Angelman’s syndrome

A

Maternal allele is not expressed, paternal allele was inactivated. Presents as mental retardation, seizures, ataxia, and inappropriate laughter.

175
Q

What is the difference between Southern blot, Northern blot, and Western blot?

A

Southern blot: DNA sample, DNA probe
Northern blot: RNA sample, DNA probe
Western blot: protein sample, Ab probe

176
Q

Pathogenesis and symptoms of Zellweger syndrome

A

Peroxisomal disease in which infants are unable to properly form myelin in CNS.
SX: hypotonia, seizures, hepatomegaly, MR, early death

177
Q

Pathogenesis and treatment of Refsum disease

A

Defect in peroxisomal alpha oxidation leading to neurological disturabnces in response to accumulation of phytanic acid.
TX: strict avoidance of chlorophyll in diet

DIT FACTS (16 decks)

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