Ataxia‐telangiectasia is a rare autosomal‐recessive disorder caused by mutations in the ATM gene on chromosome 11q22.3 (MIM 208900).1 The ataxia telangiectasia‐mutated (ATM) protein is a serine‐threonine protein kinase, which phosphorylates more than 700 substrates and is a key player in the cellular response to double‐stranded DNA damage.2 The clinical and genetic features of ataxia‐telangiectasia vary, and two forms of the disease have been described. This evidence concerns the gene ATM and Ataxia-telangiectasia.