dbMMR-Chinese

dbMMR-Chinese catalogs DNA mismatch repair (MMR) gene variants observed in the Chinese population to support research on ethnic-specific MMR variation and associated cancer risk.

Key Features:

• Cohort Composition: Compiles variant data from 33,998 Chinese individuals (23,938 cancer cases and 10,060 non-cancer cases) collected between January 1997 and May 2019.
• Comprehensive Variant Catalog: Identifies 540 MMR variants distributed across MLH1 (194), MSH2 (181), MSH6 (59), and PMS2 (53 single-base/indel changes), plus 53 large deletions/duplications.
• Standardization and Reannotation: Standardizes variant nomenclature to Human Genome Variation Society (HGVS) format and reannotates variants according to American College of Medical Genetics and Genomics (ACMG) guidelines.
• Comparative Analysis: Performs comparisons with non-Chinese MMR data revealing significant differences in variant spectrum, variant types, clinical classification, and founder mutations.
• Pathogenicity Insights: Reports a pathogenic/likely pathogenic carrier rate of 1.6% in the Chinese population.
• Ethnic Specificity: Finds that over 90% of identified variants are unique to the Chinese ethnicity, indicating ethnic-specific genetic predispositions relevant to MMR-related cancer prevention and treatment.

Scientific Applications:

• Genomic Research: Enables studies of ethnic variation in genomic stability and its implications for cancer development.
• Clinical Genetics: Supports personalized risk assessment and management for MMR-related cancers in Chinese patients.
• Public Health: Informs targeted screening programs and preventive measures based on Chinese-specific genetic predispositions.

Methodology:

Systematic data mining, HGVS nomenclature standardization, ACMG-guided reannotation, and comparative analyses with non-Chinese MMR variant datasets.