HNF1B and renal cysts and diabetes syndrome: Loss of function or a truncated HNF1b allele can result in maturity onset diabetes of the young, type 5 (MODY5), which is an autosomal dominant disorder (Bell et al. 1991; Edghill et al. 2006; Edghill et al. 2008; Bingham and Hattersley 2004; Chantelot et al. 2005), characterized by early onset usually 17–25.8 years old and is often accompanied by genital malformation.