The NHGRI Next Generation Mendelian Genetics project uses exome resequencing to identify variants in unsolved Mendelian diseases. Neonatal diabetes mellitus (ND) is a rare form of monogenic diabetes (90,000-260,000 live births) that is diagnosed in the first 6 months of life. The disease has been classified as transient or permanent and although it can be inherited, more frequently is sporadic as a result of 'de novo' mutations. Defects in 12 genes have been found as responsible for the disease (defects in the paternally imprinted chromosomal region 6q24, IPF1, SLCA2A, INS, EIF2AK3, GCK, FOXP3, GLIS3, PTF1A, HNF1Beta, KCNJ11 and ABCC8). The two subunits of the ATP-sensitive K channel (ABCC8 and KCNJ11) and the insulin gene (INS), account for almost half of the cases and similar to CHI, the other half, remains genetically unexplained. We became part of this study when we submitted 4 DNA samples for exome sequencing, from patients with NDM of Caucasian ancestry, which had no mutations identified in ABCC8 or KCNJ1, with the goal to identify new mutations in known genes or new mutations or genetic variants in new genes.

Next Generation Mendelian Genetics: Neonatal Diabetes