BRCA1 and hyperinsulinemic hypoglycemia, familial, 4: Close mutation pairs were explored among alterations generated by various mutagenic effects previously described in DT40 cells: BRCA1 deficiency [23], mismatch repair (MMR) deficiency [35], cisplatin and cyclophosphamide (CPA) [22], methyl methanesulfonate (MMS) [36] and a novel DT40 treatment for this study, UVC radiation (Tables A, B, C and D in S1 Text).