Prenatal phenotypic overlap of Costello syndrome and severe Noonan syndrome by tri-dimensional ultrasonography.

Background Prenatal diagnosis of multiple congenital anomalies is difficult, and usually molecular biology cannot immediately confirm the suspected syndrome. Fetal dysmorphology is useful tool in the diagnosis process, with limitations. Methods We report the thorough prenatal investigation by 2D and 3D ultrasonography in a case of suspected Costello syndrome. Results Prenatal abnormalities were: increased nuchal translucency, polyhydramnios, bilateral pyelectasis and ventriculomegaly. Ultrasonographic morphological fetal face analysis found abnormal thickness of the skin in the prefrontal area, thick dysplastic ears, thick lips and deep-set creases in the hands and feet. As Costello and Noonan syndromes overlap, a PTPN11 analysis was done, with presence of a mutation (T854C). Conclusion Prenatal overlap of feature of severe Noonan syndrome and Costello syndrome is confirmed, with dysmorphological similarities, due to edema of fetal skin in face and extremities. Copyright © 2006 John Wiley & Sons, Ltd.