Characteristics and Impacts of X-linked Hypohidrotic Ectodermal Dysplasia (XLHED) in Boys: An Observational International Study

This is an observational, multicentre, international study over a 2-year follow-up period. The aim of this study is to understand how XLHED affects the lives of young male patients and their families over time. By studying the natural course of the disease and its impact, the study could improve the understanding of the challenges faced by these patients and their families.

Inclusion Criteria: * Boy * Age at inclusion: from birth to the day before the 11th birthday * XLHED disease that has been diagnosed by: * genetic testing or * symptoms (sweating ability, teeth and hair impairment) and genetic diagnosis of the mother Exclusion Criteria: * Any previous treatment with ER004 or participation in a clinical trial testing ER004 * Testing for XLHED disease with a negative result