Chromosomes/Genetics Flashcards
Retinoblastoma
13
Osteogenesis Imperfecta
AD
Decreased production of type 1 collagen. Brittle bone dz, blue sclerae
Prader-Willi
Paternal deletion on cs 15, maternal imprinting (maternal gene silenced via methylation)
Angelman
Maternal gene is deleted/mutated on cs 15, paternal imprinting
Lesch-Nyhan Syndrome
XLR
Defective purine salvage due to absent HGPRT (converts hypoxanthine to IMP and guanine to GMP ==> excess uric acid prod and de novo purine synth
Orotic Aciduria
AR
defect in UMP synthase, converts orotic acid to UMP
Get orotic acid in urine, megaloblastic anemia that doesn’t improve with folate or B12, FTT
OTC deficiency: get hyperammonemia AND orotic acid in urine/blood
I-cell disease
inherited LSD, defect in phosphotransferase ==> failure of golgi to phosphorylate mannose residues on glycoproteins, protons secreted extracellularly rather than delivered to lysosomes
Coarse facial fx, clouded corneas, restricted joint mvmt, high plasma lysosomal enzymes, often fatal in childhood
Huntington Disease
AD, cs 4, CAG repeat
decreased levels of GABA and ACh
neuronal death via NMDA-R binding and glutamate toxicity. Atrophy of caudate nuclei on imaging
CS 7 mutations:
CF, Ehlers-Danlos syndrome, osteogenesis imperfecta
CS 16 mutations:
PCKD, tuberous sclerosis
CS 20 mutation:
MODY
Friedreich Ataxia
AR, cs 9, GAA repeat, degen of cerebellum and spinal cord tracts
Encodes frataxin: mitochondrial iron regulation, buildup of iron –> free radical damage
Presents in childhood w/ kyphoscoliosis
mm weakness, loss of DTRs, vibration, propriocep. Staggering gait, falling, nystamus, dysarthria, hammer toes, pes cavus, HCOM
ras
proto-oncogene,
bladder, lung, colon, pancreas, kidney cancer
N-myc
proto-oncogene
neuroblastoma, small cell lung carcinoma
BRCA-1 and 2
Tumor suppressors, DNA repair genes
breast and ovarian cancer