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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. 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. 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.


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






4. 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






5. 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.






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






7. 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)


8. 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


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






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






11. 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






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






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






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






15. X- linked mutated dystrophin. Less severe than Duchenne's. Onset: adolescence - early adulthood.


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






17. 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


18. 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






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






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






22. 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






23. 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






24. 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






25. (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!






26. 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






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






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. 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






30. 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






31. 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






32. 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






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






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






35. 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'






36. 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.






37. Mitochondrial inheritance (only transmitted via mom); degeneration of retinal ganglion cells / axons; acute loss of central vision


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






39. 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






40. 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).






41. 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)


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






43. 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


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






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. 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






47. 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






48. 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.






49. 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'






50. 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