A family with novel homozygous deletion mutation (c.1255delT; p.Phe419Serfs12) in the glucokinase gene, which is a rare cause of permanent neonatal diabetes mellitus

Heterozygous inactivating mutations in the glucokinase gene cause the mildest form of maturity-onset diabetes of the adolescents. However, homozygous or compound heterozygous mutations in the glucokinase gene are a rare cause of permanent neonatal diabetes mellitus. Herein, we present the case of a male child with permanent neonatal diabetes mellitus whose mutational analysis revealed a novel homozygous deletion mutation in the glucokinase gene. The male proband of Turkish ancestry from consanguineous parents was born at 37 weeks gestation with a birth weight of 1870 g (