Maad Rayan Publishing Company Biomedicine Advances 3080-0382 3 4 2026 10 01 A Novel EDA Variant Causing X-Linked Hypohidrotic Ectodermal Dysplasia: Case Report 161 164 10.34172/bma.87 EN Nastaran Eivazi https://orcid.org/0009-0002-8978-7825 Erfan Zaree Elham Safarzadeh Rassol Molatefi https://orcid.org/0000-0002-3614-5039 Journal Article 10.34172/bma.87 2026 03 19 2026 05 10 X-linked hypohidrotic ectodermal dysplasia (XL-HED) is a rare hereditary disorder affecting the development or function of two or more ectodermal derivatives, including teeth, hair, nails, and sweat glands. It is defined by the triad of signs that consists of abnormal or missing teeth (anodontia or hypodontia), sparse hair (atrichosis or hypotrichosis), and inability to sweat because of absence of sweat glands (anhidrosis or hypohidrosis). Their vast clinical inconsistency and etiological heterogeneity may lead to complications for the establishment of a syndromic diagnosis. In the study, we aim to report a clinical characteristic of a patient affected by EDA, which is a caring deletion at exon 2 in the Ectodysplasin A (EDA) gene on ChrX:69176876-69176977. A 12-month-old boy was referred to Bou-Ali Children’s Hospital with complaints of fever, cough, dyspnea, and lethargy. On clinical examination, he has sparse hair, conical teeth, scanty eyebrows, and low-set and overfolded ears. He had a history of recurrent hospitalization episodes (4 times) due to lobar pneumonia treated with intravenous antibiotics without abscess formation or effusion. Based on history, clinical features, and biopsy, genetic study with whole exome sequencing (WES) demonstrated a hemizygous deletion of exon 2 in EDA on ChrX: 69176876-69176977, whereas his parents did not have this deletion. Based on history, clinical features, biopsy, and genetic study, ED was diagnosed with hemizygous deletion, while his parents do not have this deletion. Molecular genetic analysis of whole exome sequencing (WES) and Sanger sequencing demonstrates hemizygous deletion of exon 2 in EDA on ChrX: 69176876-69176977.