Genotype-Phenotype Characteristics of Turkish Children With Glucokinase Mutations Associated Maturity-Onset Diabetes of the Young.

OBJECTIVE: To investigate phenotype-genotype correlations in Turkish children with glucokinase gene mutations leading to Maturity-onset diabetes in young (GCK-MODY). METHODS: Retrospective analysis of 40 patients (16 girls) aged under 18 with GCK-MODY. RESULTS: Mean (SD) serum fasting blood glucose level was 6.79 (0.59) mmol/L and the mean (SD) HbA1c level at diagnosis was 6.3% (0.5). Sixteen different variations were detected in the GCK genes of the 40 cases; 33 missense mutations, 6 deletions, and one nonsense mutation. The birthweight of infants with deletion mutation was significantly lower than that of infants with other mutations [2460 (353.66) g vs 2944.11 (502.08) g]. CONCLUSION: GCK-MODY patients with deletion mutation inherited from mothers had lower birthweight and higher fasting blood glucose than those with other inherited mutations but similar HbA1c values.