This website provides information on patients with the Hypotonia, Ataxia, and Delayed Development syndrome (HADDS, OMIM #607407), including clinical data, molecular data, management and research options.

The EBF3-related HADD syndrome caused by mutations in the EBF3 gene is a clinically heterogeneous neurodevelopmental disorder caused by either deletions in chromosomal region 10q26 or by a mutation in the EBF3 gene. EBF3 encodes a well-conserved transcription factor in the Collier/Olf/EBF family.

The syndrome is a multisystem disorder characterized by lower muscle tone (hypotonia), decreased pain sensitivity, delayed motor and language development, impaired coordination, ataxia, decreased facial movements, and distinctive facial movements. Additional features that can be seen in HADDS include misalignment of the eyes (strabismus), autistic-like features (decreased eye contact, repetitive behaviors), seizures, chronic constipation, recurrent urinary tract infections, and congenital malformations of the urogenital tract and central nervous system. Cognition can range from mild-moderate impairments to age-appropriate. It is of note that not all features are present in all individuals with EBF3-related HADDS.

This website was created to share and collect information about clinic, management and research projects to gather more knowledge and provide better treatment of patients with HADDS due to mutations in the EBF3 gene.

Hsiao-Tuan Chao, MD, PhD, Baylor College of Medicine, Houston, TX, USA, hc140077@bcm.edu

Michael F. Wangler, MD, Baylor College of Medicine, Houston, TX, USA, mw147467@bcm.edu