ATM and ataxia telangiectasia: Interestingly, the allelic frequency of the ATM variant c.5496 + 2_5496 + 5delTAAG was 0.375%, although it has not been previously reported in the population database gnomAD, the variant has been identified in cases related to ataxia-telangiectasia syndrome, familial breast cancer, and hereditary cancer predisposition syndrome.