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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.
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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. 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






2. 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


3. (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!






4. 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






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






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






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






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






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






10. 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






11. 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


12. 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






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






14. Variable presentation - incl CATCH-22: Cleft palate - Abnormal facies - Thymic aplasia / T- cell deficiency - Cardiac defects - Hypocalcemia (2ary to parathyroid aplasia) - from microdeletion at chr 22q11. Due to aberrant development of 3rd / 4th bra






15. 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






16. 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






17. 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.






18. 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






19. 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.


20. 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


21. 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.






22. 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






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






24. 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






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






26. 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






27. 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 - '






28. 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






29. 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






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


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






32. 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)


33. 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






34. 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






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. 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.






37. 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


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






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






40. 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






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






42. 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






43. 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)


44. 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






45. 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.


46. 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






47. 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).






48. 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


49. 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






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