ATM and ataxia telangiectasia: The second child shows clinical features of ataxia-telangiectasia and carries compound heterozygous mutations in ATM, where the mother contributed a c.3673C>T mutation resulting in a stop codon (p.Gln1225Ter) and the father contributed a c.8653_8654insT mutation resulting in a Val2886CysfsTer10 mutation.