Conclusion
PROS encompasses rare genetic disorders resulting from somatic, mosaic gain-of-function mutation of the PIK3CA gene. As a result of the genetic mosaicism, the clinical presentation is extremely variable. Comprehensive diagnostics are expensive, time-consuming and they place an unnecessary burden on the infant and its family. A prenatal diagnosis of this extremely rare mutation enables physicians a simplified interdisciplinary perinatal management. Moreover, it offers parents and family members to be involved in the assessment process in the context of an informed consent. Nevertheless, diagnosis of PROS remains challenging, both pre- and postnatally and unfortunately, the diagnosis is rarely made prenatally. Therefore, physicians and parents stay in the dark for a long time regarding a definitive diagnosis and promising therapy.