Congenital hyperinsulinism in the north-east Netherlands
Clinical features and DNA diagnostics in 22 children. To describe the clinical features and relevant genetic mutations in 22 children with congenital hyperinsulinism in the north-east Netherlands. Retrospective, descriptive study. Children born between June 1988 and June 2009, who were presented at the academic medical centres of Nijmegen and Groningen were included. They were clinically suspected of having congenital hyperinsulinism and DNA diagnostics were carried out. Clinical course, laboratory results, genetic data, interventions, follow-up data and patient demographics were documented. A total of 22 children from 20 families were included. Of these 22 children, 5 were born macrosomic. In 16 children the disorder was picked up within the first 4 days of life either through glucose screening of premature children or because they had symptoms. All children were treated with diazoxide; 12 (55%) did not respond to this treatment. Ultimately, 9 children underwent pancreatectomy. Five children had focal type congenital hyperinsulinism. In 15 children 13 different mutations were identified in relevant genes. We found 9 different mutations in the ABCC8-gene, including 2 novel mutations (c.2117-2A>T and c.4076C>G), 1 in the KCNJ11 gene, 1 in the GCK gene, and 2 in the GLUD1 gene. In the villages of Aalten and Silvolde a high prevalence of congenital hyperinsulinism was observed (1 in 6930), probably due to a common ancestor. The clinical characteristics of Dutch children with congenital hyperinsulinism were comparable with those reported in other study populations. We found two novel mutations in the ABCC8 gene. The mutations in the north-east Netherlands were diverse; no one mutation occurred more frequently than any other.