Hepatocyte nuclear factor 1-alpha mutation in normal glucose-tolerant subjects and early-onset type 2 diabetic patients

BACKGROUND/AIMS: The prevalence of diabetes in Korea is reported to be approximately 10%, but cases of maturity-onset diabetes of the young (MODY) are rare in Korea. A diagnostic technique for autosomal dominant MODY is being actively sought. In this regard, we used a DNA chip to investigate the frequency of mutations of the MODY3 gene (hepatocyte nuclear factor-1alpha) in Korean patients with early-onset type 2 diabetes. METHODS: The genomic DNA of 30 normal individuals [age, 24.9+/-8.6 years] and 25 patients with early-onset type 2 diabetes (age, 27+/-5.9 years) was extracted, and the MODY3 gene was amplified. The amplified DNA was hybridized onto a MODY3 chip, which has oligonucleotides of 15-25 bases, representing wild-type and mutant MODY3 sequences in both forward and reverse orientations, immobilized on its surface. RESULTS: Among the normal subjects, there was no mutation of MODY3. Among those with early-onset type 2 diabetes, there was one case of MODY3 mutation. CONCLUSIONS: Our results indicate that MODY3 mutations are not rare in Korean early-onset type 2 diabetes patients in Korea and suggest that MODY3 mutations in patients with early-onset type 2 diabetes need to be further evaluated.

The Prevalence of Maturity Onset Diabetes of the Young(MODY) 3 in Children with Type 2 Diabetes Mellitus / 소아과

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.