INS and diabetes mellitus: Both patients were followed and received insulin treatment until they were 15 2/12 and 10 9/12 years old, at which time their diagnosis of diabetes was established to be due to an ABCC8 gene mutation, identified by sequencing analysis in Exeter, U.K. Genetic studies revealed a novel homozygous missense mutation, p.E382K, in exon 7 of ABCC8 gene (12).