Phenotype heterogeneity in glucokinase–maturity-onset diabetes of the young (GCK-MODY) patients

Objective: the aim of the study was to evaluate the clinical phenotypes of glucokinase-maturity-onset diabetes of the young (gck-mody) pediatric patients from southwest poland and to search for phenotype-genotype correlations. methods: we conducted a retrospective analysis of data on 37 cgk-mody patients consisting of 21 girls and 16 boys of ages 1.9-20.1 (mean 12.5±5.2) years,treated in our centre in the time period between 2002 and 2013. results: gck-mody carriers were found in a frequency of 3% among 1043 diabetes mellitus (dm) patients and constituted the second most numerous group of dm patients,following type 1 dm,in our centre. the mean age of gck-mody diagnosis was 10.4±4.5 years. the findings leading to the diagnosis were impaired fasting glucose (ifg) (15/37),symptoms of hyperglycemia (4/37),and a gck-mody family history (18/37). mean fasting blood glucose level was 6.67±1.64 mmol/l. in the sample,there were patients with normal values (4/37),those with dm (10/37),and ifg (23/37). in ogtt,120 min glucose level was normal in 8,diabetic in 2,and characteristic for glucose intolerance in 27 of the 37 cases. twelve of the 37 cases (32%) were identified as gck-mody carriers. in the total group,mean c-peptide level was 2.13±0.65 ng/ml and hba1c was 6.26±0.45% (44.9±-18 mmol/mol). thirty-two patients had a family history of dm. dm autoantibodies were detected in two patients. the most common mutations were p.gly318arg (11/37) and p.val302leu (8/37). there was no correlation between type of mutations and plasma glucose levels. conclusion: the phenotype of gck-mody patients may vary from those characteristic for other dm types to an asymptomatic state with normal fg with no correlation with genotype. © 2017 by turkish pediatric endocrinology and diabetes society.