1274-P: Prevalence and Clinical Characteristics of Monogenic Diabetes in Chinese Population

Background: Prognosis of monogenic diabetes in Chinese is not well reported. We identified pathogenic mutations in monogenic diabetes genes in a prospective cohort of Chinese with young-onset diabetes, and compared the clinical characteristics and outcome between patients with and those without mutations. Methods: From patients enrolled in the Hong Kong Diabetes Register between 1995-2012, DNA samples of 1021 Chinese with non-type 1 diabetes diagnosed ≤40 years old were sequenced. The custom targeted panel included 34 genes related to neonatal diabetes, maturity-onset diabetes of the young, syndromes associated with diabetes and severe insulin resistance. Variants were interpreted according to standard guidelines by ACMG. Patients were followed for incident complications until 2019. Results: Pathogenic or likely pathogenic mutations in monogenic diabetes genes were detected in 33 (3.2%) patients. Mutations were more common in HNF1A (n=7) , GCK (n=6) and ABCC8 (n=5) genes. Mutation carriers had a higher female ratio (72.7 vs. 54.6%, p=0.05) and lower age at enrollment (37.9±10.6 vs. 41.5±10.4 years, p=0.05) but were similar age at diagnosis (31.5±7.3 vs. 33.1±6.0 years, p=0.13) and in diabetes duration (5.0[1.0-11.0] vs. 6.0[1.0-13.0] years, p=0.29) at baseline compared to non-carriers. Mutation carriers had lower BMI (23.6±3.5 vs. 26.0±4.8 kg/m2, p