Abstract: Ectrodactyly, ectodermal dysplasia and clefting（EEC） syndrome is characterized by split hand-split foot malformation, congenital ectodermal dysplasia and cleft lip with or without cleft palate. The etiology of it is
still obscure, but one causative gene has been cloned. So far, three suspicious loci and one gene has been identified. The penetrance and expressivity of this disorder has considerable difference among populations. Furthermore,
it is difficult to diagnose as there are some EEC like syndromes. Therefore, clear elucidation of EEC syndrome′s clinical and genetic features will be helpful to make diagnosis and give a direction for proceeding research