This website provides information on patients with genetic variants in the HX repeat motif of the ATN1 gene, otherwise known as CHEDDA (congenital hypotonia, epilepsy, developmental delay, digit abnormalities), including clinical data, molecular data, and management and research options.

CHEDDA is a congenital multisystem disorder characterized by congenital central hypotonia, epilepsy, developmental delay/ intellectual disability, digit anomalies (e.g. overlapping toes) and other congenital anomalies including of the brain, palate, heart, kidney, gastrointestinal and skeletal systems.

Not all individuals with CHEDDA will have all these features.

This condition is distinct from Dentatorubral-Pallidoluysian Atrophy, or DRPLA, an inherited condition where the first symptoms typically start in adulthood, including involuntary movements, mental and emotional problems, and a decline in thinking ability. DRPLA is caused by a different type of genetic change in the ATN1 gene, called a ‘CAG trinucleotide repeat expansion’.

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 congenital ATN1 related disorder (CHEDDA).

Fowzan Alkuraya, MD, PhD, Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia, FAlKuraya@kfshrc.edu.sa

Elizabeth Emma Palmer, MD, Genetics of Learning Disability Service, Sydney, Australia, Elizabeth.palmer1@health.nsw.gov.au

Stefan Arold, PhD, King Abdullah University of Science and Technology (KAUST), Computational Bioscience Research Center (CBRC), Division of Biological and Environmental Sciences and Engineering (BESE), Thuwal, Saudi Arabia, Stefan.arold@kaust.edu.sa