Genetic causes of maturity onset diabetes of the young may be less prevalent in American pregnant women recently diagnosed with diabetes mellitus than in previously studied European populations

Context: There are many causes of impaired glucose tolerance in pregnant women. It is unclear whether genetic etiologies are a source of impaired glucose tolerance in pregnant women.

Objective: To prospectively determine the prevalence of maturity onset diabetes of the young (MODY) due to glucokinase (GCK) mutations in an American population of women with recent onset diabetes mellitus and gestational diabetes. We hypothesized that based on America's higher prevalence of gestational diabetes mellitus (GDM) and Type 2 diabetes, there may be an increased prevalence of GK mutations in our population than in previously reported studies from European studies.

Design: Over a three-year period, 72 pregnant women with recently diagnosed diabetes mellitus were prospectively assessed for presence of the most common pathogenic GCK mutations.

Setting: This study was performed in a gestational diabetes clinic in Urban America and a high-risk pregnancy clinic that served the military and their families on an American military base in Germany.

Patients: Seventy-two women; 65 with diagnosis of diabetes mellitus in this pregnancy (GDM/overt diabetes) and 7 with diagnosis in the last nine years prior to pregnancy were recruited during pregnancy and blood samples were obtained.

Interventions: None.

Main outcome measures: Each study participant's blood sample was analyzed with restriction fragment length polymorphism to assess for mutations in the GCK gene.

Results: There were 38 female and 34 male neonates born at 38 weeks gestation ± 1.2 weeks. Mean birth weight was 3351 g ± 450 g. There were no patients with GCK mutations found in our population 0/72. This prevalence is not greater than that seen in previous a similar study in European women with gestational diabetes, but in fact significantly less (p = 0.03).

Conclusion: American women with recently diagnosed diabetes mellitus likely have no higher prevalence of MODY than in previously studied European women with diabetes mellitus and may have a lower prevalence.