Background: Congenital hyperinsulinism (HI) is the most common cause of persistent hypoglycemia in infants and children.
Objective and hypotheses: Recently, mutations in genes usually involved in MODY 1 and 3 have been described in HI.
Method: We present here six cases of hyperinsulinism associated with MODY1 (one case) and MODY3 (four cases) and one case of HI associated with MODY5 mutation.
Results: Case 1: Girl (BW 3350g, GA 36 weeks) with neonatal hypoglycemia due to congenital HI owing to HNF4a mutation (c.131G>C). HI was diazoxide-responsive, and the treatment could be stopped after 3 years. Case 2: Boy (BW 3670g, GA 41 weeks) with neonatal hypoglycemia due to transient congenital HI owing to HNF1b duplication (c.1-?-1674+?dup). He required diazoxide for 10 days. His mother has the same HNF1b duplication, and gestational diabetes during a subsequent pregnancy. Case 3 and 4: Brother (BW 2990g, GA 39 weeks) and sister (BW 2800g, GA 38 weeks), with neonatal hypoglycemia due to HI owing to HNF1a mutation (c.598C>T), requiring diazoxide treatment for a few months for the girl. Case 5: 4.8-year-old boy with hypoglycemia (convulsion) due to HI owing to HNF1a mutation (c.502C>T), still requiring diazoxide treatment 5 years later. Hypoglycemia was associated with ketonuria, and was initially believed to be secondary to GH and ACTH deficiency. Case 6: 5-year-old boy with hypoglycemia due to HI owing to HNF1a mutation (c.77T>C), still requiring diazoxide treatment after 1.5 years. Initially, hypoglycemia was believed to be secondary to GH and ACTH deficiency.
Conclusion: We report the first case of HI associated with HNF1b mutation. HNF4a and HNF1a are recently described causes of HI. Our cases showed that the clinical presentation can be variable, from transient neonatal HI to persistent HI discovered during childhood.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology