Congenital hyperinsulinism in a Nigerian infant: A case report and review of literature

Abstract

Congenital hyperinsulinism, a rare genetic disorder characterized by excess insulin secretion even during hypoglycemic episodes, has two histological subtypes; diffuse and focal. Genotypes denote which of the two subtypes presents, and this is the first case being reported in Nigeria. The aims of this study were to report the first case of genetically confirmed compound heterozygote inheritance for two non-sense mutations in the ABCC8 gene in a Nigerian child and her family. A full-term average weight (7.5 lb) female baby presented with severe hyperinsulinemic hypoglycemia [HH] after birth and failed medical treatment with dextrose infusion. She had several hypoglycemic seizure episodes and spastic diplegic cerebral palsy, despite frequent feeding. Following physiotherapy, her spasticity was regressing and she was also able to say polysyllabic words. Genetic testing done 2 years after birth showed that her father was heterozygous for the ABCC8 non-sense mutation, P.W143*, and her mother was heterozygous for the P.Q416* ABCC8 mutation. This report shows the need for quick and early genetic testing for rare disorders and the possibility of collaboration with more specialized genetic laboratories. When diagnosed, diffuse or focal diazoxide unresponsive hypoglycemia may be treated by partial or complete pancreatectomy with the potential complication of diabetes mellitus later in life.