In addition, mutations in DNA damage signalling kinase ATM have been linked to Ataxia-telangiectasia, whereas Ataxia-telangiectasia-like disorder (ATLD) and Nijmegen breakage syndrome (NBS) are caused by mutations in two components of the MRN complex, MRE11 and NBS1 respectively. This evidence concerns the gene ATM and ataxia telangiectasia.