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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. 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

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

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

4. 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

5. Scurvy - swollen gums - bruising - anemia - poor wound healing. In fruits / vegetables. Facilitates Fe absorption: keeps Fe2+ reduced state - more absorbable. Also involved in hydroxylation of proline - lysine in collagen synthesis; antioxident; need

6. Bleeds (gamma - carboxylation of glutamic acid residues on factors II - VII - IX - X - protein C - S). Neonatal hemorrhage (inc PT - aPTT - normal bleeding time - sterile intestine in newborn - can't synthesize vitK - synthesized by intestinal flora

7. 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.

8. Inclusion cell disease. Can't add mannose -6- P to lysosome proteins. Enzymes secreted outside of cell instead of targeted to lysosome. Lysosomal storage disorder. Coarse facial features - clouded corneas - restricted joint movement - high plasma lev

9. Trisomy 18 (E=election age) - 1:8000. Severe MR - rockerbottom feet - congenital heart disease. Vs Patau's: micrognathia - low - set ears - clenched hands - prominent occiput. Death w/in 1 yr

10. Lysosomal storage disease (a mucopolysaccharidosis). Aut - rec deficiency of alpha - L- iduronidase; heparan sulfate - dermatan sulfate accumulate. Developmental delay - gargoylism (thickened gingiva + upturned nose) - airway obstruction - corneal cl

11. 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.

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

13. 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)

14. Hemolytic anemia (inc fragility of erythrocytes - vit E is antioxidant - protects erythrocytes / membranes from free - radical damage). Muscle weakness - neurodysfunction tooo.

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

16. X- linked recessive - absence of HGPRT (hypoxanthine to IMP - guanine to GMP in purine salvage pathway). Can't salvage purines - so increased elimination = incr uric acid production. Retardation - self - mutilation - aggression - hyperuricemia - gout

17. Converts adenosine to inosine in purine salvage pathway. Excess ATP - dATP in nucleotide pool = imbalance (feedback inhibition of ribonucleotide reductase - preventing DNA synthesis) - so decreased lymphocyte count (major cause of SCID - severe combi

18. Aut - rec absence of galactose -1- phosphate uridyltransferase; toxic substances accumulate (e.g. galactitol in lens of eye). FTT - jaundice - hepatomegaly - infantile cataracts - MR. Tx: no galactose / lactose (glucose + galactose).

19. 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.

20. Pantothenate; in CoA. Dermatitis - enteritis - alopecia - adrenal insufficiency

21. Peroxisomal disease; no alpha - oxidation of branched - chain FA like phytanic acid. Neuro sx; Tx = avoid chlorophyll

22. Protein malnutrition. Skin lesions - edema - liver malfunction (fatty change). Small child - swollen belly.

23. Acquired (e.g. liver dz) or hereditary (urea cycle enzyme deficiencies). inc. NH4 depletes alpha - keotglutarate - inhibiting TCA cycle. Ammonia intox - tremor - slurred speech - somnolence - vomiting - cerebral edema - blurred vision. Tx with benzoa

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

25. Aut - rec fructokinase deficiency. Can't P- late fructose - so can't enter cells. Benign - asymptomatic - just fructose in blood - urine.

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

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

28. Aut - dom. Facial lesions (adenoma sebaceum) - hypopigmented 'ash - leaf spots' on skin - cortical / retinal hamartomas - seizures - MR - renal cysts - renal angiomyolipomas - cardiac rhabdomyomas. Inc. incidence astrocytomas. Incomplete penetrance w

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

30. (Pyruvate + NAD+ + CoA --> acetylCoA + CO2 + NADH; 3 enzymes - requires B1 -2 -3 - CoA - lipoic acid). Pyruvate - alanine accumulate --> lactic acidosis (pyruvate to lactate). Congenital or acquired (e.g. alcoholics - B1 deficiency - lactic acidosis!

31. Aut - dom - Fibrillin defect (scaffolding for elastin formation - stretchy protein for lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava). Connective tissue disorder: skeleton - heart - eyes affected. Tall - long extremities

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

33. Aut - rec; can't convert orotic acid to UMP in de novo pyrimidine synthesis pathway (defect in orotic acid PRT or orotidine 5''- P- decarboxylase. Incr. orotic acid in urine - megaloblastic anemia (that doesn't get better with B12 / folate supplement

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

35. Aut - dom cell - signaling defect in fibroblast growth factor receptor 3 (FGFr3). Dwarfism: short limbs but head/trunk normal. A/W advanced paternal age

36. Skeletal muscle glycogen phosphorylase deficiency (normally breaks down glycogen to 4- glucose residue branched 'limit dextrans'). Type V glycogen storage disease. Incr. glycogen in mm - but can't break down (mm cramps - myoglobinuria with strenuous

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

38. 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

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

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

41. X- linked dominant disorder (M/F offspring of affected mom can be affected; all female offspring of affected father diseased). Inc. phosphate wasting at proximal tubule; rickets - like presentation

42. 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

43. Energy malnutrition. Tissue / muscle wasting - loss of subQ fat - variable edema.

44. 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.

45. 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

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

47. 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

48. Microdeletion of long arm of chr 7 (incl. elastin gene). 'Elfin' faces - MR but good verbal skills - cheerful disposition - extreme friendliness w/ strangers - CV problems

49. B1 (thiamine) deficiency. Polyneuritis - symmetrical muscle wasting

50. 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'