Clinically, heterozygous germline mutations in HNF1β cause familial forms of type 2 diabetes called as maturity-onset diabetes of the young, subtype 5 (MODY5), which is frequently associated with congenital abnormalities, such as polycystic kidney, pancreatic hypoplasia and genital tract abnormality [45-47]. Here, HNF1B is linked to type 2 diabetes mellitus.