ABSTRACT
BACKGROUNDS: Gestational diabetes mellitus (GDM) is defined as glucose intolerance with onset or first detection during pregnancy and mostly caused by insulin resistance and beta-cell dysfunction like type 2 diabetes. However, autoimmune or monogenic diabetes can contribute to GDM. Maturity-onset diabetes of the young (MODY) is a monogenic form of diabetes characterized by an early age of onset and an autosomal dominant pattern of inheritance. Most MODY cases are attributable to mutations in HNF-1alpha gene, also known as MODY3. We investigated whether mutations in HNF-1alpha gene are present in Korean women with GDM. METHODS: A total of 96 Korean women with GDM who have a family history of DM were screened for mutations in the HNF-1alpha gene. We evaluated the clinical characteristics of GDM women with HNF-1alpha gene mutations. RESULTS: Five of 96 patients (5.2%) were found to have a mutation in HNF-1alpha gene. Four of those (-23C > G, 833G > A (Arg278Gln), 923C > T, IVS5 + 106A > G) were novel and one (-124G > C) in promoter region was reported in previous study. The mean age of GDM women with mutations of HNF-1alpha gene was 34 years. Four women with MODY3 gene mutations required insulin therapy during pregnancy. GDM women with MODY3 gene mutations appeared to be decreased insulin secretion (HOMA-%B) than those without mutations. CONCLUSIONS: We have found the existence of MODY3 as well as novel HNF-1alpha gene mutations in Korean women with GDM.