hydrolethalus syndrome 1
Definition A rare syndrome (OMIM:236680) characterised by CNS malformation, hydrocephalus and polydactyly which is postaxial in the hands and preaxial in the feet. The highly characteristic hallux duplex, is seen in almost no other condition. In half, the heart has a large atrioventricular communis defect. The pregnancy is characterised by hydramnios, which is often massive, and preterm delivery.
Molecular pathology Defects of HYLS1, which encodes a protein of unknown function, cause hydrolethalus syndrome 1.