Quiz 2 Diseases

Question 1

Familial Hypercholesterolemia

Answer 1

Mechanism of cholesterol uptake is disrupted

• HIGH LDL b/c there is a defect in the LDL receptors
• can lead to atherosclerotic plaques

Question 2

Zellweger Spectrum Disorders

Answer 2

Peroxisome Biogenesis Disorders

• defects in the assembly of peroxisome
• ~12 diff. proteins involved in assembly
• most serious form –> absence or reduced number of peroxisomes in cells
• no cure, death by 1 year

Question 3

Down Syndrome

Answer 3

47XX +21 (Trisomy 21)

• Most common
• Strongly associated with increased maternal age
• Results most commonly from maternal meiotic nondisjunction (in the ovum)
• Also due to unbalanced translocation
• Varying degrees of cognitive impairment
• Structural abnormalities: increased nuchal translucency, cardiac defects, duodenal atresia, ventriculomegaly, absent nasal bone, short limbs

Question 4

Turner Syndrome

Answer 4

45XO

• Monosomy X – always female because no Y
• Short stature, ovarian hypofunction – no puberty – infertile
• Webbed neck, no cognitive defects

Question 5

Klinefelter Syndrome

Answer 5

47XXY

• varying presentation
• Primary hypogonadism (low T)
• Small and/or undescended testes
• Gynecomastia, infertility
• Tall stature
• Variability of X numbers can increase symptoms

Question 6

Thalassemia

Answer 6

underproduction of hemoglobin

Question 7

Methemoglobinemia

Answer 7

cannot bind heme

Question 8

Sickle Cell Anemia

Answer 8

mutated HbS –> sickle-shaped RBC’s (rigid)

Glu (acidic, polar) –> Val (hydrophobic) = MISSENSE MUTATION

Question 9

Postaxial Polydactyly

Answer 9

Autosomal Dominant Inheritance

Question 10

Tyrosinase-Negative Albinism

Answer 10

Autosomal Recessive Inheritance

Question 11

LHON

Answer 11

Leber Hereditary Optic Neuropathy

• mtDNA mutation (complex I)
• NADH dehydrogenase mutation
• acute loss of vision in early adulthood

Question 12

MERRF

Answer 12

Myoclonic Epilepsy and Ragged Red Fibers

• mtDNA mutation (tRNA in Lysine - disrupts synthesis of cytochrome-c oxidase)
• myoclonus dinted muscle movement (ataxia) + seizures

Question 13

MELAS

Answer 13

Mitochondrial Encephalopathy, Lactic Acidosis and Stroke-like activity

• mtDNA mutation (tRNA for Leucine –> complex I and cytochrome-c oxidase)
• affects nervous system + muscle function
• severe headaches, seizures, vomiting, hemiparesis
• MOST COMMON MITOCHONDRIAL DISEASE)

Question 14

Xeroderma Pigmentosum

Answer 14

NER (Nucleotide Excision Repair)

-NER complex that recognizes distortions

Question 15

Hereditary nonpolyposis colorectal cancer

Answer 15

MER = Mismatch Excision Repair

• Autosomal Dominant Inheritance
• MER complex (MutL/MutS)

Question 16

Cockayne Syndrome

Answer 16

TCR = Transcription-Coupled Repair

• works with BER, NER and other repairs
• Cockayne –> NER - RNA polymerase is permanently stalled @ sites of damage in important genes
• growth retardation, skeletal abnormalities, sensitivity to sunlight

Question 17

BRCA associated breast cancer

Answer 17

Recomination Repair

Question 18

Shiga Toxin

Answer 18

Binds to Eukaryotic 60s

-blocks translocation

Question 19

Ricin

Answer 19

Binds to Eukaryotic 60s

-blocks translocation

Question 20

Puramycin

Answer 20

causes premature chain termination in BOTH Eukaryotes and Prokaryotes

Question 21

Streptomycin

Answer 21

Binds to Prokaryotic 30s

-inhibits initiation

Question 22

Tetracycline

Answer 22

Binds to Prokaryotic 30s

-inhibits initiation

Question 23

Erythromycin

Answer 23

Binds to Prokaryotic 50s

-blocks translocation

Question 24

Clindamycin

Answer 24

Binds to Prokaryotic 50s

-blocks translocation

Question 25

Chloramphenicol

Answer 25

inhibits Prokaryotic peptide transferases

Question 26

Cycloheximide

Answer 26

inhibits Eukaryotic peptide transferases

Question 27

Diptheria Toxin

Answer 27

inactivates EF2-GTP

Question 28

Duchenne Muscular Dystrophy

Answer 28

FRAMESHIFT MUTATION - large in-frame and out-of-frame deletions in dystrophin gene --> little/no expression of the dystrophin protein - most sever form of MD - muscle wasting (wheelchair bound by 12) - a less severe form (truncated form of dystrophin) = Becker Muscular Dystrophy - X-LINKED RECESSIVE

Question 29

I-Cell Disease

Answer 29

Defective lysosomal transport because lack of M6P - proteins not targeted to lysosome - high plasma levels of lysosomal enzymes - by 6 months: failure to thrive and developmental delays and physical manifestations - death by 7 years old

Question 30

Ehlers-Danlos Syndrome | Epidermolysis Bullosa Simplex

Answer 30

ED Syndrome - over flexible joints EB Simplex - blisters on skin BOTH caused from Lysol hydroxylates defects - bone, skin and joint disorders

Question 31

Prader-Willi Syndrome

Answer 31

Deletion of a region of chromosome 15 (paternal) - Short stature, hypotonia, small hands/feet - Obesity, uncontrolled eating - Mild to moderate intellectual disability

Question 32

Angelman Syndrome

Answer 32

Deletion of a region of chromosome 15 (maternal) - Severe intellectual disability, seizures, ataxia - Uncontrollable laughter

Question 33

Edwards Syndrome

Answer 33

Trisomy 18 (47, XX +18) - Often IUGR, most die in utero, if born, live up to 1 year - Microencephaly, prominent occiput, malformed and low-set ears, small mouth and jaw, cleft lip/palate, rocker bottom feet, overlapped fingers

Question 34

Patau Syndrome

Answer 34

Trisomy 13 (47, XX +13) - Severe developmental abnormalities - Most die before birth, prenatal death within 1 week - Heart abnormalities, kidney malformations, CNS dysfunction - Microcephaly, malformed ears, closely spaced/absent eyes, clenched hands and polydactyl, cleft lip/palate

Question 35

Retinoblastoma

Answer 35

Autosomal Dominant Inheritance | -90% Penetrance

Question 36

Neurofibromatosis

Answer 36

Variable Expressivity | -growth-like tumors that vary in size, shape, color, etc.

Question 37

Marfan Syndrome

Answer 37

Variable Expressivity - affects the connective tissue, + other tissues - Ectopia lentis, weakened and stretched aorta - May lead to aneurysm and aortic dissection

Question 38

Osteogenesis Imperfecta

Answer 38

Locus Heterogeneity - "Brittle Bone Disease" - Mutations in collagen genes (two loci: chromosome 7 and 17) - Either mutation exhibits similar phenotypes (varying severity)

Question 39

Osteogenesis Imperfecta

Answer 39

Locus Heterogeneity - "Brittle Bone Disease" - Mutations in collagen genes (two loci: chromosome 7 and 17) - Either mutation exhibits similar phenotypes (varying severity)

Question 40

Cystic Fibrosis

Answer 40

Recessive inheritance of disease (i.e. aa)

Question 41

Pyloric Stenosis

Answer 41

Multifactorial Inheritance - muscular hypertrophy b/t stomach and duodenum - 5x more common in males than females - Males need less risk genes to show disease; females need more risk genes