Genetics Flashcards
Type I familial dyslipidemia
hyper-chylomicronemia. Lipoprotein lipase deficiency or altered apolipoprotein C-II. Causes pancreatitis, hepatosplenomegaly, and eruptive/pruritic xanthomas (no I risk for atherosclerosis) .
Type IIa familial dyslipidemia
familial hypercholesterolemia. Autosomal dominant; absent LDL receptors. Causes accelerated atherosclerosis, tendon (Achilles) xanthomas, and corneal arcus.
Type IV familial dyspipidemia
hypertriglyceridemia. Hepatic overproduction of VLDL. Causes pancreatitis.
Fabry’s disease
a-galactosidase A. Peripheral neuropathy of hands/feet, angiokeratomas, cardiovascular/renal disease; XR
Gaucher’s disease
Glucocerebrosiclase. Hepatosplenomegaly, aseptic necrosis of femur, bone crises, Gaucher’s cells (macrophages that look like crumpled tissue paper); AR
Niemann-Pick disease
Sphingomyelinase; Progressive neurodegeneration, epatosplenomegaly, cherry-red spot on macula, foam cells ; AR
Tay-Sachs disease
Hexosaminiclase A; Progressive neuroclegeneration, developmental delay, cherry-red spot on macula, lysosomes with onion skin, no hepatosplenomegaly (vs. Niemann-Pick); AR
Krabbe’s disease
beta-galactocerebrosiclase; Peripheral neuropathy, developmental delay, optic atrophy, globoid cells; AR
Metachromatic leukodystrophy
Arylsulfatase A; Central and peripheral demyelination with ataxia, dementia; AR
Hurler’s syndrome
alpha-L-iduronidase; Developmental delay, gargoylism, airway obstruction, corneal clouding, hepatosplenomegaly; AR
Sturge-Weber syndrome
Congenital disorder with port-wine stains (aka nevus flammeus), typically in V 1 ophthalmic
distribution; ipsilateral leptomeningeal angiomas, pheochromocytomas. Can cause glaucoma, seizures, hemiparesis, and mental retardation. Occurs sporadically.
Tuberous sclerosis
HAMARTOMAS : Hamartomas in CNS and skin; Adenoma sebaceum (cutaneous angiofibromas); Mitral regurgitation; Ash-leaf spots; cardiac Rhabdomyoma; (Tuberous sclerosis); autosomal dominant; Mental retardation; renal Angiomyolipoma; Seizures
Neurofibromatosis type I (von
Recklinghausen’s disease)
Cafe-au-lait spots, Lisch nodules (pigmented iris hamartomas), neurofibromas in skin, optic
gliomas, pheochromocytomas. Autosomal dominant, 100% penetrant, variable expression.
Mutated NF-I gene on chromosome 17.
von Hippei-Lindau disease
Cavernous hemangiomas in skin, mucosa, organs; bilateral renal cell carcinoma,hemangioblastoma in retina, brain stem, cerebellum; pheochromocytomas. Autosomal dominant; mutated tumor suppressor VHL on chromosome 3 .
Duchenne’s Muscular dystrophy
Pseudohypertrophy of calf muscles; cardiac myopathy; Gowler’s maneuver; onset before 5 yrs. Duchenne’s = Deleted Dystrophin. Dystrophin gene (DMD) is the longest known human gene (increased rate of spontaneous mutation). Dystrophin helps anchor muscle fibers, primarily in skeletal and cardiac muscle
