NO EVIDENCE FOR MUTATIONS IN A PUTATIVE SUBUNIT OF THE BETA-CELL ATP-SENSITIVE POTASSIUM CHANNEL (K-ATP CHANNEL) IN JAPANESE NIDDM PATIENTS

The ATP-sensitive K channel (K-ATP channel) in pancreatic beta cells i s believed to play a crucial role in glucose stimulated insulin releas e. We investigated whether defects in the recently cloned gene for a p utative subunit of this channel (KATP-2) could be a cause of diabetes in Japanese patients. The coding region of this beta-cell type channel gene was investigated in 192 diabetics with a family history of the d isorder by single-stranded conformational polymorphism (SSCP) analysis . Two silent polymorphisms were found and confirmed by sequencing, but no missense or nonsense mutations were detected The allele frequency of the polymorphisms was compared with 96 control subjects without a f amily history of the disease, and no clear difference was found These results indicate that genetic defects of the KATP-2 channel may not be a major cause of diabetes in Japan. (C) 1995 Academic Press, Inc.