Ectodermal dysplasias are a clinically and genetically very heterogeneous group of disorders. In addition to EDA1 and EDAR testing, GeneDx now offers a diagnostic test for WNT10A-related ectodermal dysplasia. Individuals with WNT10A mutations usually have oligodontia, nail dystrophy, dry skin, excessive or reduced sweating and sparse hair. According to recent studies, mutations in the WNT10A gene have been identified in 9% of patients with ectodermal dysplasia and in as many as 25% of individuals who tested negative for a mutation in the EDA1 gene. Once a mutation in WNT10A has been detected in a proband, carrier testing of relatives and prenatal diagnosis are also available.