Maturity‐onset diabetes of the young type 5 in a family with diabetes and mild kidney disease diagnosed by whole exome sequencing

Exome sequencing is being increasingly used to identify disease‐associated gene mutations. We used whole exome sequencing to determine the genetic basis of a syndrome of diabetes and renal disease affecting a mother and her son. We identified a mutation in the hepatocyte nuclear factor 1‐b ( HNF1B ) gene that encoded a methionine to valine amino acid change ( M 160 V ) in the HNF1B protein. This leads us to the previously unappreciated diagnosis of maturity‐onset diabetes of the young type 5 and provided a basis for genetic counselling of other family members.