RESUMO
PURPOSE: Maturity-onset diabetes of the young(MODY) is a subtype of type 2 diabetes defined by autosomal dominant mode of inheritance, onset of diabetes usually before the age of 25 yrs, and a primary defect in the function of the beta cells of the pancreas. MODY3 is known as the most common form and is caused by mutations in hepatocyte nuclear factor(HNF)-1alpha. We examined the prevalence of MODY3 in children with type 2 diabetes mellitus(DM). METHODS: Children with type 2 DM(N=17) and their family members with type 2 DM(N=5) were enrolled. Inclusion criteria for the children were fasting C-peptide and postprandial C-peptide more than 1.0 ng/mL and 1.5 ng/mL respectively, familial type 2 DM in at least two generations, and body mass index(BMI)(kg/m(2)) less than 95th percentile. Genomic DNA was extracted from blood samples. We analyzed HNF-1alpha for mutation by DNA microarray method and direct sequencing. RESULTS: We found one case with a mutation of the promoter region of HNF-1alpha(5'-ctaGGCTAGTGGGGTTTTGCGGGGGCAGTGGGTGCAAGG-3') in one child's family member among 22 children and adult subjects with type 2 DM. CONCLUSION: Although we found a mutation of HNF-1alpha in an adult family member with type 2 DM, we did not find this mutation in a child with type 2 DM. The further investigation of MODY in children, including other types, is required.