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Biochemistry Diseases

Subject : health-sciences
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This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. Pantothenate; in CoA. Dermatitis - enteritis - alopecia - adrenal insufficiency

2. Microdeletion of short arm of chr 5: 46 -XX or XY - 5p -. Microcephaly - moderate/severe MR - high pitched crying/mewing (cry of the cat) - epicanthal folds - cardiac abnormalities

3. Lysosomal storage disease (a sphingolipidosis). Aut - rec deficiency of arylsulfatase A - cerbroside sulfate accumulates. Central / peripheral demyelination - ataxia - dementia.

4. Chr 15 - normally active maternal (AngelMan = maternal) allele deleted. MR - seizures ataxia - inappropriate laughter ('happy puppet'). Other parent's allele inactivated / imprinted by methylation; can also be from uniparental disomy (2 copies of chr

5. Aut - rec deficiency of phenylalanine hydroxylase / THB (cofactor) - so can't convert phenylalanine to tyrosine. Results: accumulate phenylalanine (excess phenylketones in urine); tyrosine becomes essential AA. Dx: MR - growth retardation - seizures

6. Pyridoxine = B6. Convulsions - hyperirritability - peripheral neuropathy. Deficiency inducible by INH - oral contraceptives. Converted to pyridoxal phosphate: used in transamination (ALT - AST - etc) - decarboxylation - glycogen phosphorylase - heme

7. Aut - rec deficiency of homogentisic acid oxidase (degradative pathway of tyrosine) - benign disease. Dark connective tissue - pigmented sclera - urine turnes black on standing - may have debilitating arthralgias.

8. Lysosomal storage disease (a sphingolipidosis). X- linked recessive (all other sphingolipidoses AR); deficiency of alpha - galactosidase A ceramide trihexoside accumulates. Peripheral neuropathy (hands / feet) - angiokeratomas - CV / renal disease

9. Glucose -6- phosphatase deficiency (type I glycogen storage disease). Can't de - plate G6P (glycogenolysis & gluconeogenesis). Severe fasting hypoglycemia - inc. glycogen in liver - inc. blood lactate (gluconeogenesis impaired) - hepatomegaly.

10. Hypercalcemia - hypercalciuria - loss of appetite - stupor. Seen in sarcoidosis (inc. activation of vitamin D by epithelioid macrophages).

11. Adult polycystic kidney disease. Aut - dom - 90% from mutation in APKD1 - chr 16 (16 letters in 'polycystic kidney'). Always bilateral - big kidneys (lots of big cysts). Flank pain - hematuria - HTN - progressive renal failure. a/w polycystic liver d

12. Peroxisomal disease; can't metabolize very long chain FA (VLCFAs) or branched - chain FAs (e.g. phytanic acid - via alpha - oxidation). Can't form myelin in CNS. Hypotonia - seizures - hepatomegaly - MR - early death.

13. Aut - rec galactokinase deficiency. Galactitol can accumulate if galactose present in diet; relatively mild. Galactose in blood / urine - infantile cataracts (may not track objects - develop social smile.

14. Aut - rec (CFTR gene - chr 7; CFTR channel secretes Cl - in lungs / GI - resorbes Cl - from sweat). Thick mucus - plugs lungs - pancreas - liver. Recurrent pulm infections (Pseudomonas - S aureus) - chronic bronchitis - bronchiectasis - pancreatic in

15. Lysosomal storage disease (a sphingolipidosis). Aut - rec deficiency of galactocerebosidase; galactocerebroside accumulates. Peripheral neuropathy - developmental delay - optic atrophy - globoid cells (multinucleated).

16. Glycogen debranching enzyme (alpha -1 -6 glucosidase) deficiency (type III glycogen storage disease). Like type I (Von Gierke's; glucose -6- phosphatase deficiency) but milder (gluconeogensis intact; normal blood lactate levels)

17. Type I familial dyslipidemia. Lipoprotein lipase deficiency or altered apolipoprotein C- II (LPL cofactor) = can't degrade TG circulating in chylomicrons - VLDLs. Increased chylomicrons - elevated cholesterol / TGs in blood

18. Type IIa familial dyslipidemia. Aut - dom absence / decrease in LDL receptors. LDLs increased - blood cholesterol elevated.

19. Microtubule polymerization defect (no lysosomal tracking). Decreased phagocytosis. Recurrent pyogenic infections - partial albinism - peripheral neuropathy.

20. Lysosomal storage disease (a mucopolysaccharidosis). X- linked rec deficiency of iduronate sulfatase; heparan sulfate - dermatan sulfate accumulate. Mild Hurler's phenotype (developmental delay - gargoylism (thickened gingiva + upturned nose) - airwa

21. Aut - rec deficiency in apoB-100 (binds LDL receptor; mediates VLDL secretion) and apoB-48 (mediates chylomicron secretion) - so can't synthesize lipoproteins. Sx appear in 1st months of life: FTT - steatorrhea - acanthocytosis (= RBC with spikes - '

22. Lysosomal storage disease (a sphingolipidosis). Aut - rec deficiency of hexosaminidase A; GM2 ganglioside accumulates. Progressive neurodegeneration - developmental delay - cherry- red spot on macula - lysosomes with 'onion skin'

23. Night blindness - dry skin

24. Aut - dom; mutation of NF2 gene (chr 22: 'type 2 = 22'). Bilateral acoustic neuromas - juvenile cataracts.

25. Macrocytic - megaloblastic anemia w/o neuro sx. #1 vitamin deficiency in USA; see in alcoholism / pregnancy (neural tube defects; supplement in early pregnancy) - also drugs (phenytoin - sulfas - MTX). From FOLiage (leafy greens) with small reserve p

26. Cheilosis - corneal vascularization (the 2 C's)

27. Rickets in children (bending bones); osteomalacia in adults (soft bones). Also hypocalcemic tetany.

28. Faulty collagen synthesis: hyperextensible skin - tendency to bleed (easy bruising) - hypermobile joints. Mostly type III collagen. 6 types - inheritance / severity vary (AD/AR). A/w joint dislocation - berry aneurysms - organ rupture

29. Mutation in nucleotide excision repair proteins (endonucleases that release oligonucleotides containing damaged bases; DNApol + ligase fill in). Can't repair thymidine dimers (UV light). Dry skin with melanoma + other cancers ('children of the night'

30. Dec alpha - ketoacid dehydrogenase activity = blocked degradation of branched amino acid (Ile - Leu - Val = I Love Vermont; maple trees w/ branches). Increased alpha - ketoacids in blood (esp Leu). Severe CNS defects - MR - death. Urine smells like m

31. Trisomy 21; MR - flat facies - epicanthal folds - simian crease - gap btwn 1-2nd toes - duodenal atresia - congenital heart dz (esp septum - primum - type ASD) - a/w inc risk All - Alz dz (>35 y/o). #1 cause congenital MR; #1 chr disorder (1:700). 95

32. Type IV familial dyslipidemia. Hepatic overproduction of VLDL; VLDL increased; blood TGs elevated

33. Variable inheritance (locus heterogeneity); vs ocular albinism (x- linked recessive). Congenital deficiency of either 1) tyrosinase (can't make melanin from tyrosine; aut - rec); 2) defective tyrosine transporters (dec. tyrosine = dec. melanin); can

34. A 22q11 deletion syndrome. Thymic - parathyroid - cardiac defects. Microdeletion at chr 22q11. Due to aberrant development of 3rd / 4th branchial pouches.

35. Immobile cilia (dynein arm defect). Infertility (M/F; sperm immotile) - bronchiectasis - recurrent sinusitis (not pushing out bacteria / particles). A/W situs inversus

36. Severe vitamin B3 (niacin) deficiency (less severe = glossitis). Diarrhea - dementia - dermatitis. Can be caused by Hartnup disease (dec. tryptophan absorption) - malignant carcinoid syndrome (inc tryptophan metabolism) (B3 made from tryptophan) and

37. X- linked rec; most common urea cycle disorder (others aut - rec). Can't eliminate ammonia; often dx'd perinatally but can be later. Dx: orotic acid in blood / urine (excess carbamoyl phosphate converted to orotic acid) - dec. BUN - hyperammonemia sx

38. Lysosomal storage disease (a sphingolipidosis) - Aut - rec deficiency of beta - glucocerebrosidase; glucocerebroside accumulates. Hepatosplenomegaly - aseptic necrosis of femur - bone crises - Gaucher's cells (macrophages that look like crumpled tiss

39. A 22q11 deletion syndrome. Palate - facial - cardiac defects. Microdeletion at chr 22q11. Due to aberrant development of 3rd / 4th branchial pouches.

40. High output cardiac failure (dilated CM) - edema

41. Aut - rec deficiency of aldolase B; fructose -1- P accumulates; dec. in phosphate = inhibition of glycogenolysis / gluconeogenesis. Hypoglycemia - jaundice - cirrhosis - vomiting. Tx: limit fructose - sucrose (gluc + fruc) intake.

42. 'Bear liver'guy - arthralgias - fatigue - headaches - skin changes - sore throat - alopecia. Also teratogenic (cleft palate - cardiac abnormalities)

43. X- linked recessive. G6PD: G6P + NADP+ -> 6PG + NADPH; NADPH needed to reduce GSSG to 2GSH (glutathione reductase) for H2O2 to 2H2O conversion. Only pathway for making reduced GSH in RBC - so can't detoxify free radicals / peroxides (fava beans - sul

44. X- linked trinucleotide repeat disorder (CGG); affects methylation / expression of FMR1 gene - a/w chromosomal breakage. #2 cause of genetic MR (Down's is #1). Macro - orchidism - long face + large jaw - large everted ears - autism.

45. Aut - dom; defective / absent LDL receptor. Elevated LDL. Heterozygotes (1:500) have cholesterol = 300 mg/dL. Homozygotes (rare) chol > 700 mg /dL - severe atherosclerotic dz early in life - tendon xanthomas (classically Achilles); may have MI < 20 y

46. Aut - dom; I/II/III - familial tumors of endocrine glands (pancreas - parathyroid - pituitary - thyroid - adrenal medulla). II / III a/w ret gene

47. Aut - dom; disorder of blood vessels. Telangiectasia - recurrent epistaxis - skin discolorations - AVMs. Incr. in Utah Mormons

48. Defects in type IV collagen synthesis; most common form X- linked recessive. Hereditary nephritis - deafness +/- ocular disturbances (type IV collagen important in BM of kidney - ears - eyes)

49. Aut - dom; mutation of huntingtin (chr 4 - 'hunting 4 food') - CAG repeats. Depression - progressive dementia - choreiform movements - caudate atrophy; manifests 20-50 y/o. Dec GABA - ACh in brain.

50. Brittle bone disease; genetic bone disorder. Variety of gene defects. Type II fatal in utero - neonatal. Most common form: AD with abnormal type I collagen (bone): multiple fractures w/ minimal trauma (e.g. during birth) - blue sclerae (translucent c