A case of a Japanese patient with neonatal diabetes mellitus caused by a novel mutation in the ABCC8 gene and successfully controlled with oral glibenclamide

Permanent neonatal diabetes mellitus (PNDM) is a rare form of insulin-dependent diabetes mellitus that presents within the first 6 months after birth and may require lifelong insulin treatment. Approximately 40% of all PNDM cases are caused by activating mutations in either the KCNJ11 gene or ABCC8 gene, which encode the Kir6.2 or sulfonylurea receptor (SUR) 1 subunit of the ATP-sensitive potassium channel (KATP channel), respectively (1,2,3). The KATP channel is expressed on the surface of pancreatic beta cells. In this context, a heterozygous gain-of-function mutation in ABCC8 or KCNJ11 causes PNDM. High-dose oral sulfonylurea has been reported to be an effective treatment agent for PNDM with ABCC8 and KCNJ11 gene mutations compared with insulin injection (4). Here we report a patient with PNDM caused by a novel heterozygous missense mutation in ABCC8 and controlled with oral glibenclamide for more than 3 yr.