Ataxia-telangiectasia is an autosomal recessive disorder caused by pathogenic variants in the gene ATM. It is a pan-ethnic disease with a higher prevalence among the Sephardic-Jewish population. Affected individuals generally present with symptoms between ages one and four years, including an inability to control purposeful eye movements, the presence of involuntary movements, and telangiectasias of the conjunctivae. The disease also associated with immunodeficiency, which causes individuals to have frequent infections and be at increased risk for malignancies, specifically leukemia and lymphoma. Most individuals live beyond 25 years, and there have been several documented cases of patients surviving into their 50s. Genotype-phenotype correlations have been established. Several specific variants have been associated with the age of onset and/or severity of the disease.
For information about carrier frequency and residual risk, please see the residual risk table.