ATM and immune system disorder: Homozygous or compound heterozygous ATM GPVs cause a rare autosomal recessive disorder called A-T, characterized by progressive cerebellar ataxia, telangiectasia, oculomotor apraxia, immunodeficiency, cancer susceptibility, and radiation sensitivity [118]; therefore, counseling ATM GPV carriers against the risk of autosomal recessive conditions in their offspring is recommended [14].