Abstract
RASopathy is a group of syndromes that are caused by germline mutations in genes that encode components of the RAS/MAPK signaling pathway. This pathway is key for cell regulation, proliferation, differentiation, and survival.
For the great heterogeneity of phenotypic manifestations, the clinical diagnosis prevailed in the past years after birth, but the detection of these syndromes is possible also prenatally. Ultrasound examination of the fetus during screening tests plays a major role.
Typical common features and indication criteria for RASopathy sequencing include pathological nuchal translucency measurement, lymphatic jugular sacs enlargement, development of cystic hygroma, effusions or fetal hydrops, polyhydramnios, congenital heart disease, and renal pathology. In pathological prenatal screening, even with normal karyotype results, additional ultrasound and genetic fetal examination are appropriate.