Decoding 22q11.2: prenatal profiling and first-trimester risk assessment from a Danish nationwide cohort.

The cFTS markers in pregnancies with a classic 22q11.2 duplication resembles the common trisomies with decreased levels of PAPP-A. The classic 22q11.2 deletions, however, have increased levels of PAPP-A, which likely limits early prenatal detection using the current cFTS risk algorithm. The scope for improving early detection of classic 22q11.2 deletions from targeted risk algorithms using NT, PAPP-A, and β-hCG seems limited. This demonstrates the capability, but also the limitations, of the cFTS markers in detecting atypical chromosomal anomalies, which is important knowledge when designing new prenatal screening programs. This article is protected by copyright. All rights reserved.