Prenatal diagnosis of Prader‐Willi syndrome due to uniparental disomy with NIPS: Case report and literature review.

Background: PWS is challenging to diagnose prenatally due to a lack of precise and well‐characterized fetal phenotypes and noninvasive markers. Here we present the case of prenatal diagnosis of Prader‐Willi syndrome, which was suspected with whole‐genome NIPS. Methods: Whole‐genome noninvasive prenatal screening showed a high risk for trisomy 15. Amniocentesis followed by FISH analysis and SNP‐based chromosomal microarray was performed. Results: Simultaneous analysis of maternal and fetal samples with SNP microarrays demonstrated maternal uniparental disomy (UPD). Conclusion: The presented case is the first case of PWS described in detail, which was suspected by NIPS results. It demonstrates that the choice of confirmation methods concerning the time needed is crucial for the right diagnosis. We suppose that prenatal testing of UPD is essential for chromosome regions, which play a key role in the appearance of various gene‐imprinting failure syndromes like PWS or AS. [ABSTRACT FROM AUTHOR]