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Biochemistry Diseases

Subject : health-sciences
Instructions:
  • Answer 50 questions in 15 minutes.
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  • 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 in APC gene (chr 5 - 'polyp' has 5 letters). Colon covered with adenomatous polyps after puberty. Progresses to colon cancer unless resected






2. 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.






3. 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)


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






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






6. 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






7. 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






8. Age dep or hereditary lactose intolerance (blacks / Asians); lose brush - border enzyme. Bloating - cramps - osmotic diarrhea. Avoid dairy / use lactase pills.






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






11. Trisomy 13 (P = puberty age) - 1:15 -000. Severe MR - rockerbottom feet - congenital heart disease. Vs. Edwards': cleft lip / Palate - holoProsencephaly - Polydactyly (P's) - micropthalmia - microcephaly. Death w/in 1 yr


12. Mutation in mismatch repair genes (mismatched nucleotides in unmethylated / newly synthesized string recognized + removed)






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






14. Aut - dom; mutation on long arm of chr 17 (17 letters in 'von recklinghausen') cafe - au - lait spots - neuronal tumors - Lisch nodules (pigmented iris hamartomas). Skeletal disorders (eg scoliosis) - optic pathway gliomas - pheochromocytoma - increa


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






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






17. 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






18. (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!






19. 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






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






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






22. 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






23. 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.


24. 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






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






26. 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






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






28. 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






29. 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






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






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


32. 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






33. 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






34. 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






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






36. 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






37. 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


38. 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


39. Facial flushing (niacin 'flushing' in pharm doses for hyperlipidemia treatment).






40. 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.






41. 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






42. 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






43. 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.






44. 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






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






46. 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


47. Inhibits lipoic acid (required for pyruvate dehydrogenase complex - pyruvate to acetyl - coA). Vomiting - rice water stools - garlic breath.






48. 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


49. 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






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