3.3. Association between the MTNR1B Polymorphism, Fasting Plasma Glucose, and Type-2 Diabetes in Another Elderly Population (Replication Cohort 2). Exploratory Analysis of the Influence of Parity in the Effects of the Polymorphism on Type-2 Diabetes. The gene discussed is MTNR1B; the disease is type 2 diabetes mellitus.