Sanger sequencing showed that c.863G>A was inherited from heterozygous mutations in the paternal line and c.2506C>T from heterozygous mutations in the maternal line.<h4>Conclusion</h4>The child was a CHI with a biallelic recessive heterozygous mutations in ABCC8 resulting in impairment of its encoded ATP-sensitive potassium (KATP) channel, poor response to diazoxide treatment, and developed diabetes after subtotal pancreatectomy. Here, ABCC8 is linked to diabetes mellitus.