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Biochemistry Diseases

Subject : health-sciences
Instructions:
  • Answer 50 questions in 15 minutes.
  • If you are not ready to take this test, you can study here.
  • Match each statement with the correct term.
  • Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

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






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






3. 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






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






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

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6. 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






7. Aut - dom - defect in spectrin or ankyrin. Hemolytic anemia - increased MCHC (mean corpuscular hemoglobin concentration). Splenectomy is curative






8. 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.






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

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10. 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






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

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12. 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

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






14. 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'






15. Aut - rec - defect in renal tubular AA transporter (cysteine - ornithine - lysine - arginine in renal PCT). inc. cystine (2 cysteines w/ disulfide bond) in urine --> cystine kidney stones (cystine staghorn calculi). Common (1:7000); Tx with acetazola






16. 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






17. Delayed wound healing - hypogonadism - dec. adult hair (axillary / facial / pubic); ?predispose to alcoholic cirrhosis?






18. 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)

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19. 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






20. 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.






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






22. 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






23. 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

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






25. 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






26. Lysosomal storage disease (a sphingolipidosis). Aut - rec deficiency of sphingomyelinase; sphingomyelin accumulates. Progressive neurodegeneration - hepatosplenomegaly - cherry- red spot on macula - foam cells.






27. 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)

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28. (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!






29. Aut - dom; mutation in APC gene (chr 5 - 'polyp' has 5 letters). Colon covered with adenomatous polyps after puberty. Progresses to colon cancer unless resected






30. 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






31. Cobalamin = B12. macrocytic - megaloblastic anemia. Neuro sx: paresthesias - subacute combined degeneration from abnormal myelin. Prolonged deficiency = irreversible nervous system damage. Found in animal products; synthesized only by microorganisms.






32. 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






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






34. 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

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35. Aut - dom; deletion of VHL gene (tumor suppressor) on chr 3 (3 words for chr 3). Results in constitutive expression of HIF (transcription factor) - activation of angiogenic growth factors. Hemangioblastomas of retina / cerebellum / medulla - 50% get






36. 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






37. 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






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






39. 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

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40. Rare; from abx or excessive raw egg ingestion (avidin in whites binds biotin). Dermatitis - alopecia - enteritis. Biotin used in carboxylation enzymes.






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






42. 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.

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






44. Aut - rec - 3 forms. All interfere with conversion of methionine to cysteine - cysteine becomes essential; homocysteine accumulates. Causes: 1) cystathionine synthase deficiency (Tx: dec Met - inc. Cys intake. Inc B12 / folate in diet to drive conver






45. 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

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46. 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






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. 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.






49. Chr 15 - normally active parental (Prader = parental) allele deleted. MR - hyperphagia - obesity - hypogonadism - hypotonia. Other parent's allele inactivated / imprinted by methylation; can also be from uniparental disomy (2 copies of chr from 1 par






50. 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