Genetic disorders — Flashcards

Flashcard 11: Fragile X syndrome

Answer:

Extra: macroorchidism, long face, large jaw, large ears, autism, mitral valve prolapseXD, triplet repeat disorder(CGG repeats in) FMR1mnemonic: X-Girlfriend's First Aid Helped Ace My Test

Flashcard 12: achondroplasia

Answer:

Extra: dwarfism with short limbs, large head, normal torsoadvanced paternal ageADFGF-3

Flashcard 13: Down syndrome

Answer: 95% due to nondisjunction but my be due to Robertsonian translocation or mosiacism

Extra: mental retardation, flat face, prominent epicanthal folds, simian crease, gap between first two toespregnancy quad screen: increased - β-hCG, inhibin A decreased - α-fetoprotein, urine estriol ultrasound: increased nuchal translucency in first trimester nearly normal lifespan but early Alzheimer's diseaseadvanced maternal agetrisomy 21

Flashcard 14: Individuals with Down syndrome are predisposed to develop what conditions?

Answer: ALL and early onset Alzheimer's disease

Flashcard 15: What disease is most classically associated with meiotic nondisjunction?

Answer: Down syndrome (trisomy 21)

Flashcard 16: A child presents with a recessive disorder when only one parent is a carrier. What are three possible explanations?

Answer: infidelity, uniparental disomy, sporadic mutation

Flashcard 17: osteogenesis imperfecta

Answer:

Extra: multiple unexplained fractures, blue sclerae, hearing loss, dental defects (may be confused with child abuse)usually ADglycosylation step of Type I collagen synthesis