Fetal chromosome Abnormalities

Question 1

1. Most common sex chromosome abn

2. Only viable monosomy

Answer 1

1. Klinefelter 47 XXY

2. Turner 45 X

Question 2

Quad screen
Serum analytes
Timing

Answer 2

hCG, uE3 (unconjugated estriol), AFP, DIA (dimeric inhibit A)

15-22+6

Question 3

Ultrasound markers of down

Answer 3

Hypoplastic or absent nasal bone

Echogenic bowel, ventriculomegaly and thickened NT prompt further evaluation

Major structural anomalies include duodenal atresia and cardiac anomalies such as septal defects, tetralogy of Fallot, and atrioventricular canal defects