biochem step

Question 1

Cr 3

Answer 1

VHL, renal cell CA

Question 2

Cr 4

Answer 2

ADPKD, achondroplasia, Huntington

Question 3

Cr5

Answer 3

cri-du-chat syndrome, familial adenomatous polyposis

Question 4

Cr6

Answer 4

hemochromatosis

Question 5

Cr 7

Answer 5

Williams syndrome, cystic fibrosis

Question 6

Cr 9

Answer 6

Friedreich ataxia, tuberous sclerosis

Question 7

Cr 11

Answer 7

Wilms tumor, B-globin gene defects (sickle cell, beta thal), MEN1

Question 8

Cr 13

Answer 8

Patau syndrome, Wilson dz, retinoblastoma (RB1), BRCA2

Question 9

Cr 15

Answer 9

Prader-Willi syndrome, Angelman syndrome, Marfan’s

Question 10

Cr 16

Answer 10

ADPKD, A-globin gene defects (A-thal), tuberous sclerosis (TSC2)

Question 11

Cr 17

Answer 11

NF 1, BRCA1, TP53 (Li Fraumeni syndrome)

Question 12

Cr 18

Answer 12

Edwards syndrome

Question 13

Cr 21

Answer 13

Down syndrome

Question 14

Cr 22

Answer 14

NF 2, DiGeorge (22q11)

Question 15

X chromosome

Answer 15

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

Question 16

Von Gierke (type 1)

Answer 16

severe fasting hypoglycemia, hepatomegaly, renomegaly / low enzyme: G6P

Question 17

Pompe dz (type 2)

Answer 17

cardiomyopathy, hypotonia, exercise intolerance, enlarged tongue / low enzyme: lysosomal acid A-1-4-glucosidase

Question 18

Cori dz (type 3)

Answer 18

mild sx, normal blood lactate levels
low enzyme: debranching ones (A-1-6-glucosidase, 4-A-D-glucanotransferase)

Question 19

Andersen dz (type 4)

Answer 19

hepatosplenomegaly + failure to thrive in early infancy / low enzyme: branching enzyme

Question 20

McArdle dz (type 5)

Answer 20

painful mm cramps, myoglobinuria, arrhythmia
low enzyme: myophosphorylase

Question 21

Tay Sachs

Answer 21

sx - neurodegeneration, developmental delay, hyperreflexia, cherry red spot, no HSM
low enzyme - hexosaminidase A
high substrate - GM2 ganglioside

Question 22

Fabry dz

Answer 22

sx - episodic peripheral neuropathy, angiokeratomas, hypohidrosis
low enzyme - A-galactosidase A
high substrate - cramide trihexoside

Question 23

Metachromatic leukodystrophy

Answer 23

central & peripheral demyelination w/ ataxia & dementia
low enzyme - Arylsulfatase A

Question 24

Krabbe dz

Answer 24

sx - peripheral neuropathy, destroyed oligodendrocytes, developmental delay
low enzyme - galactocerebrosidase

Question 25

Gaucher dz

Answer 25

sx - HSM, osteoporosis, avascular necrosis of femur, bone crises, Gaucher cells low enzyme - Glucocerebrosidase

Question 26

Niemann Pick dz

Answer 26

sx - neurodegeneration, HSM, foam cells low enzyme - sphingomyelinase