3 - Obs - Screening tests - Chromosomal Abnormalities

Question 1

Downs - Trisomy ?, ? common among live births. Result of non-dysjunction at ? , occasionally (6%) from ?chromosomal ? in parents. More common w ? maternal age. Affected infant has ?retardation, characteristic ?and often (50%) congenital ?disease. Unless due to parental balanced translocation, recurrence risk is ? and determined largely by maternal ?.

Answer 1

21
most
meiosis
balanced 
translocation
advancing/incr

mental
faces
cardiac
low
age

Question 2

Other chromo abnorms

Trisomy ? (Edward’s) and Trisomy 13 (?) more common w ? maternal age. Ass w major ? defects, and affected fetuses ? in utero or shortly after ?. Sex chromosome abnormalities inc ? syndrome (47XXY) – ? w normal intellect, small ? and infertile. ? (single X Cr: X0) – female, ? , normal intellect.

Answer 2

18
patau's
incr
structural
die
birth
Klinefelter's
males
testes
Turners
infertile

Question 3

What is the triple test ? when is it reserved for ? why?

Answer 3

blood at 16w inc AFP, hCg, oestriol

reserved for after 14w when nuchal USS not available

Question 4

What signs on USS incr risk of Downs? (4)

Answer 4

thickened nuchal translucency
tricuspid regurgitation
absent or shortened nasal bone
structural abnorms