Prenatal diagnosis of Greig Cephalopolysyndactyly Syndrome. When to suspect it

Greig Cephalopolysyndactyly Syndrome (GCPS) is a very rare multiple congenital anomaly with an estimated incidence of 1-9:1,000,000 in newborns with principal findings of macrocephaly, ocular hypertelorism, and polysyndactyly (preaxial or mixed preaxial and postaxial). Very few cases of prenatal diagnoses have been reported. The postnatal diagnosis is based on clinical findings and family background. GLI3, the only gene associated with this anomaly, is altered in more than 75% of cases. Deletions over 1 Mb and involving other genes yield severe clinical cases, which are known collectively as Greig Cephalopolysyndactyly-contiguous gene Syndrome. We report a case in which, despite early polydactyly findings on week 16, the diagnosis was established during the third trimester of pregnancy due to the late presentation of other anomalies corresponding to this syndrome.