Biochem fast facts

Question 1

Adenosine deaminase deficiency

Answer 1

SCID:

infections

Question 2

Absent HGPRT

Answer 2

Lesh-Nyan:

self-mutilation, ID, hyperuricemia

Question 3

Phosphotransferase defect

Answer 3

I-cell disease (lysosomal SD):

coarse face, clouded corneas, dec. joint movement

Question 4

Type 1 collagen defect

Answer 4

OI Type 1:

fractures, blue sclera

Question 5

Type IV collagen defect

Answer 5

Alport Syndrome

Question 6

Ab to Type IV collagen

Answer 6

Goodpasture’s syndrome

Question 7

Type III collagen deficiency

Answer 7

Vascular Ehler’s Danlos (Three ED):

vascular/organ rupture

Question 8

Type V collagen mutation

Answer 8

Classical Ehler’s Danlos:

joint and skin symptoms

Question 9

Impaired copper absorption/transport –> dec. lysyl oxidase activity

Answer 9

Menke’s disease:

kinky hair, hypotonia, GR

Question 10

Fibrillin defect

Answer 10

Marfan’s

Question 11

Excess elastase activity

Answer 11

Emphysema

Question 12

3 diseases involving faulty collagen synthesis

Answer 12

Scurvy: hydroxylation prob
OI: triple helix prob
Ehlers Danlos: cross-linking prob

Question 13

Protein malnutrition

Answer 13

Kwashiorkor

Question 14

Total calorie malnutrition

Answer 14

Marasmus

Question 15

Fructokinase defect

Answer 15

Essential fructosuria:

Fructose in blood and urine

Question 16

Aldolase B deficiency

Answer 16

Fructose intolerance:

hypoglycemia, jaundice after eating honey/juice

Question 17

Galactokinase deficiency

Answer 17

That’s the name of the ds.

Galactose in blood and urine, infantile cataracts

Question 18

Galactose-1-phosphate uridyltransferase absence

Answer 18

Classic galactosemia:

infantile cataracts, FTT, jaundice, ID

Question 19

What toxin accumulates in both galactokinase deficiency and essential galactosemia?

Answer 19

Galactitol

Question 20

N-acetylglutamate deficiency

Answer 20

That’s the name of the ds:

hyperammonemia

Question 21

Ornithine transcarbamylase deficiency

Answer 21

That’s the name of the ds:

orotic acid in blood and urine, dec BUN, hyperammonemia

Question 22

Phenylalanine hydroxylase deficiency

Answer 22

PKU:

eczema, mousy odor

Question 23

Tetrahydrobiopterin cofactor deficiency

Answer 23

PKU:

eczema, mousy odor

Question 24

Homogentisate oxidase deficiency

Answer 24

Alkaptonuria:

urine turns black, dark CT

Question 25

Cystathionine synthase deficiency

Answer 25

Homocystinuria:

kyphosis, lens subluxation, ID

Question 26

Homocysteine methyltransferase deficiency

Answer 26

Homocystinuria:

kyphosis, lens subluxation, ID

Question 27

Defect of intestinal aa transporter for cysteine, ornithine, lysine, and arginine

Answer 27

Cystinuria:

hexagonal cystine stones

Question 28

Deficiency of alpha-ketoacid dehydrogenase (inc. Ile, Leu, Val)

Answer 28

Maple syrup urine disease:

CNS defects, burnt sugar urine

Question 29

Glucose-6-phosphate deficiency

Answer 29

Von Gierke disease (type 1):

severe hypoglycemia, inc. glycogen in liver, high lactate

Question 30

Lysosomal alpha-1,4-glucosidase deficiency

Answer 30

Pompe disease (type 2): 
cardiomyopathy

Question 31

Debranching enzyme (alpha-1,6-glucosidase deficiency)

Answer 31

Cori disease (type 3):
milder hypoglycemia, normal lactate

Question 32

Skeletal muscle glycogen phosphorylase deficiency

Answer 32

McArdle disease (type 5):
red urine, muscle cramps, arrhythmia

Question 33

Alpha-galactosidase A deficiency

Answer 33

Fabry disease:

peripheral neuropathy, angiokeratomas

Question 34

Glucocerebrosidase (B-glucosidase) deficiency

Answer 34

Gaucher disease:

femur necrosis, tissue paper lipid macrophages, HSmegaly

Question 35

Sphingomyelinase deficiency

Answer 35

Niemann-Pick disease:

cherry red macula, foam cells, HSmegaly

Question 36

Hexoaminidase A deficiency

Answer 36

Tay-Sachs disease:

cherry red macula, neuroprobs, NO HSmegaly

Question 37

Galactocerebrosidase deficiency

Answer 37

Krabbe disease:

developmental delay, optic atrophy, globoid cells

Question 38

Arylsulfatase A deficiency

Answer 38

Metachromatic leukodystrophy:

CNS/PNS demyelination, ataxia, dementia

Question 39

Alpha-L-iduronidase deficiency

Answer 39

Hurler disease:

gargoylism, dev. delay, corneal clouding

Question 40

Iduronate sulfatase deficiency

Answer 40

Hunter syndrome:

mild Hurler, aggressive, no corneal clouding

Question 41

Carnitine deficiency

Answer 41

That’s the ds name:

weakness, hypotonia, hypoketotic hypoglycemia

Question 42

Acyl-coA dehydrogenase deficiency

Answer 42

That’s the ds name:

dec. fasting glucose, dec ketones

Question 43

Lipoprotein lipase deficiency

Answer 43

Hyperchylomicronemia:

pancreatitis, eruptive/pruritic xanthomas, no atherosclerosis risk

Question 44

Absent/defective LDL receptors

Answer 44

Familial hypercholesterolemia:

atherosclerosis, xanthomas, corneal arcus

Question 45

Hepatic VLDL overproduction

Answer 45

Hypertriglyceridemia:

pancreatitis

Question 46

Inability to convert orotic acid to UMP

Answer 46

Orotic aciduria:

orotic acid in urine, FTT, megaloblastic anemia

Question 47

Drug that inhibits dihydroorotate dehydrogenase

Answer 47

Leflunomide: inh. pyrimidine synth

Question 48

Drugs that inhibit IMP dehydrogenase (2)

Answer 48

Mycophenolate and ribavirin: inh. purine synth

Question 49

Drug that inhibits ribonucleotide reductase

Answer 49

Hydroxyurea: inh pyrimidine synth

Question 50

6-MP MOA

Answer 50

Inhibits de novo purine synthesis

Question 51

Drug that inhibits thymidylate synthase

Answer 51

5-FU: inh pyrimidine synthesis

Question 52

Azathioprine MOA

Answer 52

Produg for 6-MP; inh de novo purine synthesis

Question 53

Dihydrofolate reductase inhibitors (3)

Answer 53

Methotrexate, trimethoprim, and pyrimethamine

Question 54

Defective pyrimidine dimer repair

Answer 54

Xeroderma pigmentosum:

dry skin, melanoma

Question 55

Defective non homologous end joining

Answer 55

Ataxia telangiectasia