Ataxia telangiectasia (OMIM 208900) is a human inherited disorder characterized by poor coordination (ataxia), red marks on the face (telangiectasia), increased sensitivity to X-rays and other radiation, and an increased susceptibility to cancer. Recent studies have shown that this disorder occurs as a result of mutation of the ATM gene. Propose a mechanism for how a mutation in the ATM gene leads to the characteristics associated with the disorder. Be sure to relate the symptoms of this disorder to functions of the ATM protein. Further, explain why DNA repair mechanisms cannot correct this problem.