Genetic characteristics and long-term follow-up of 11 patients with congenital hyperinsulinism followed in a single center.

Background: Congenital hyperinsulinism (CHI) is a rare disease with an estimated incidence of 1:40,000 live births. Here, we characterize 11 patients treated at Munich Children's Hospital Schwabing.

Methods: We analyzed data on birth, treatment and laboratory results including genetic testing and evaluated the long-term course with a follow-up visit.

Results: All patients had severe, diazoxide-(DZX)-resistant hypoglycemia, beginning immediately after birth. Two patients were treated by medical therapy, eight underwent subtotal pancreatectomy and one had a partial resection. Both patients who had medical therapy still suffer from occasional hypoglycemia. Six patients with subtotal pancreatectomy were affected by mild hypoglycemia. Seventy-five percent of patients who had surgical treatment developed diabetes mellitus (DM) at a median age of 10.5 (8-13) years. In 89% of patients with available genetic testing, mutations of the ABCC8 gene were detected.

Conclusions: The majority of CHI-patients not responding to DZX underwent surgery. After subtotal pancreatectomy, patients typically developed diabetes around early puberty.