LGA, local government area; T1DM, type 1 diabetes mellitus; T2DM, type 2 diabetes mellitus; MDM, monogenic diabetes mellitus; NGT, normal glucose tolerance; IGT, impaired glucose tolerance; OGTT, oral glucose tolerance test; HbA1c, glycosylated hemoglobin; AIRg, acute insulin response to glucose; PI, proinsulin; DI; diabetes insipidus; CHD, coronary heart disease; BMI, body mass index. The gene discussed is INS; the disease is Impaired glucose tolerance.