First Report of X-Linked Hypohidrotic Ectodermal Dysplasia with a Hemizygous c.1142G >C in the EDA Gene: Variant of Uncertain Significance or New Pathogenic Variant?

Abstract

BackgroundHypohidrotic Ectodermal Dysplasia (HED) is a genetic disorder which affects structures of ectodermal origin. X-linked hypohidrotic ectodermal dysplasia (XLHED) is the most common form of disease. XLHED Is characterized by hypotrichosis, hypohydrosis and hypodontia. The cardinal features of classic HED become obvious during childhood. Identification of a hemizygous EDA pathogenic variant in an affected male confirms the diagnosis. Case PresentationWe report on a male newborn with the main clinical characteristics of the X-linked HED including hypotrichosis, hypodontia and hypohidrosis. Gene panel sequencing identified a new hemizygous missense variant of uncertain significance (VUS) c.1142G >C (p.Gly318A1a) in the EDA gene, located on the X chromosome and inherited from the healthy mother. ConclusionDespite the potential functional impact of VUS remains uncharacterized, our goal is to evaluate the clinical potential consequences of missense VUS on EDA gene. Given the proband’s phenotype compatibility with classic HED, it is reasonable to attribute a causative role to the variant found in hemizygosis in the gene EDA. The present case demonstrates that this novel VUS could broaden the spectrum of genes mutations involved in the HED phenotype.