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ABIM - Diseases
Diseases 02
Question | Answer |
---|---|
What is homocystinuria? | Deficiency of cystathionine synthase, which uses up homocysteine and methionine. Causes mental retardation and vessel thrombosis. |
What is a common cause of increased homocysteine? | B12/folate deficiency. B12 accepts the methyl group from folate and transfers it to homocysteine to make methionine. If this transfer doesn't happen --> accumulation of homocysteine --> damage EC's --> predisposes to thromboses --> MI |
What is Pompe's disease? | Deficiency of a lysosomal enzyme that breaks down glycogen (lysosomal α 1,4 glucosidase) --> build up of glycogen --> cardiomegaly with early death |
In what patient would 6-mercaptopurine not be effective? | Lesch-Nyhan syndrome: deficiency of hypoxanthine-guanine phosphoribosyltransferase (HGPRT). Won't activate purine synthesis or 6-mercaptopurine (drug that blocks purine synthesis), which requires activation by HGPRT to become active. X-linked recessive. |
Hirschsprung disease | bowel obstruction due to aperistalsis (absence or destruction of ganglion cells that control peristalsis) --> enlargement of colon. Starts at the anus and progresses upward. Proximal bowel is dilated but has peristalsis. No signs of stool on rectal exa |
Can people with Down's have children? | Males with Down's are infertile. Females can have babies, but have 50% of having a Down's child. |
What are the possible chromosomal sets for Turner's Syndrome? | Nondisjunction: 45, X = 46 total. Mosaicism: 45, X OR 45, XX |
In Turner's Syndrome, what is the growth hormone and insulin-like growth factor profile? | Both are normal. |
In which disease do you have XXY karyotype? | Klinefelter's Syndrome. XXY with female secondary sex characteristics, hypogonadism (dec testosterone and inhibin, inc LH and FSH) |
In which disease do you have XYY karyotype? | Paternal nondisjunction -- aggressive, sometimes criminal behavior, nl gonadal fxn. |
Karyotype of a hermaphrodite | 46,XX, but has BOTH male and female gonads |
Decreased maternal folate levesl cause what? | Open neural tube defects |
What happens in testicular feminization? | X-linked recessive disorder where there is deficiency in androgen receptors. Can't sense fetal DHT and testosterone --> no Wolffian duct development and external genitalia remain female. |
Do those with testicular feminization have testicles? | Yes |
Do those with testicular feminization have Mullerian structures such as fallopian tubes, uterus, cervix, and upper vagina? | No because sertoli cells in testicles make MIF --> apoptosis of mullerian structures |
What is the most common systemic complication of IV drug use? | Hep B |
In a cocaine addict, would you expect dilated or pin pupils? | dilated. |
In a heroin addict, would you expect dilated or pin pupils? | miosis. |
Person on some drug and experience tinnitus and vertigo | ASA |
Person on some drug and experiences photosensitive rash | Tetracycline |
ASA causes what kind of acid/base disturbance? | Mixed. Stimulation of the respiratory center --> respiratory alkalosis. ASA is an acid --> metabolic acidosis. |
What is the most common cause of HTN in young women? | OCPs |
What should you think of when you see transverse bands in a patient's nails, pt is strawberry picker? | arsenic poisoning |
What should you think of when you see opasities on x-ray in the epiphyses of a child with failure to grow? | Pb poisoning. Pb is the only heavy metal that can deposit in bone. |
Child from poor neighborhood eats paint off crib or off walls. Has severe abdominal colic, cerebral edema leading to convulsions. | Pb poisoning. Check for microcytic anemia and failure to thrive. Look for Pb in intestines. |
Worker in automobile factory with exposure to batteries --> abdominal colic and diarrhea | Pb poisoning. |
Man makes alcohol in his old radiator, peripheral neuropathy | Pb poisoning. |
Get pottery from some other country; pottery painter dabs paint brush on tongue | Pb poisoning. |
Why would someone with Pb poisoning get cerebral edema? | Pb blocks ferrochelatase --> buildup of δ-amino-lebvulinic acid (ALA) --> toxic to neurons --> increase in vessel permeability in the brain |
How does UVB lead to skin cancer? | Pyrimidine dimers distort the DNA helix; inactivation of TP53 suppressor gene (enable cell to move on to S phase), activation of RAS oncogene. |
thalassemia | defect in making globin chains |
Von Hippel Lindau Syndrome | Defect in VHL gene (autosomal dominant), which regulates nuclear transcription; cerebellar hemangioblastoma, retinal angioma, renal cell carcinoma (bilateral), pheochromocytoma (bilateral). Von hippo -- around the hips bilaterally: kidneys (renal CA), ad |
Wilms tumor | Defect in WT gene (chromosome 11), which regulates nuclear transcription; tumor of the kidneys that typically occurs in children, rarely in adults. Autosomal dominant.Highly responsive to treatment with VINCRISTINE, with about 90% of patients surviving a |
Elevated AFP (alpha feto protein) | Tumor marker for hepatocellular carcinoma, yolk sac tumor of ovary or testis; also elevated in open neural tube defects (triple screen for pregnant women) |
Decreased AFP (alpha feto protein) | Down Syndrome |
Bence Jones protein | Tumor marker for multiple myeloma, Waldenstrom's macroblobulinemia; the Bence Jones' protein is the light chain of the Ig. |
CA 15-3 | Tumor marker for Breast carcinoma |
CA 19-9 | Tumor marker for Pancreatic carcinoma |
CA 125 | Tumor marker for Surface-derived ovarian cancer |
CEA | Tumor marker for colorectal and pancreatic carcinoma |
PSA | Tumor marker for prostate carcinoma (also elevated in prostate hyperplasia) |
If you suspect a trophoblastic tumor in a woman, what would you want to measure in her serum? | BhCG |
Inheritance pattern of xeroderma pigmentosum | autosomal recessive - defect in DNA repair |
Inheritance pattern of Fanconi anemia | autosomal recessive - defect in DNA repair |
Inheritance pattern of Ataxia-telangiectasia | autosomal recessive - defect in DNA repair |
Inheritance pattern of Bloom syndrome | autosomal recessive - defect in DNA repair |
GERD predisposes to which type of cancer? | Barrett's esophagus --> distal esophageal adenocarcinoma |
DDx for RLQ pain | appendicitis, Crohn's dz, ectopic pregnancy, follicular cysts, cystic teratomas of the ovaries |
Conn syndrome | adrenal adenoma that secretes mineralocorticoids |
What is the most common reason for a child to have a white eye reflex? | Congenital cataracts. Can also be due to retinoblastoma or a CMV or rubella infection. |
52 yo woman with weight loss and epigastric distress, upper GI series --> no peristalsis in stomach --> died. Tumors in stomach and ovaries. | Diffuse gastric adenocarcinoma (also called Linitis plastica). Diffuse infiltration of signet ring cells in lining of the stomach --> leather bottle stomach (very hard stomach with all the infiltration!) |
Dislocated lenses, deep vein thrombosis, stroke, atherosclerosis, mental retardation. What is the diagnosis? | Deficiency of cystathionine synthase, which uses up homocysteine and methionine. |