MLH1 and immune system disorder: To our knowledge this is the first report associating immunodeficiency with markers in many of these genes, notably MSH2, MLH1, and RAD50. We also identified new non-synonymous alleles of MSH2, MLH1, RAD50, and NBS1, and UTR SNPs in RAD50 and MRE11 that were unique to IgAD and/or CVID.