Beyond BRCA1/2, deleterious alterations in other genes have been associated with DDR deficiency: ATM and CHEK2 (sensors of DNA damage), CDK12 (positive regulator of BRCA genes), and PALB2 and FANCA (which interact with BRCA1 and/or BRCA2 during DNA repair). The gene discussed is BRCA1; the disease is hyperinsulinemic hypoglycemia, familial, 4.