Multiple choice

A chorionic villus sample is tested cytogenetically and found to have trisomy 15. This is followed up with a normal amniocentesis. Which interpretation is drawn?

  1. The fetus likely has trisomy 15, and maternal cell contamination probably explains the normal amniocensis.

  2. The fetus will likely be normal, and confined placental mosaicism probably explains the abnormal CVS result.

  3. The fetus should be tested uniparental disomy of chromosome 15, given the risk of Prader -Willi or Angelman syndromes.

  4. The abnormal CVS is probably due to pseudomosaicism and the fetus is likely to be normal.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

It is possible that the conceptus had trisomy 15, and that disomy was restored by loss of one 15. This could have resulted in uniparental disomy, which would lead to Prader-Willi or Angelman syndrome.

Keep practicing — related questions