Genome-wide association study identifies variants associated with autoimmune hepatitis type 1

Area of Science:

• Genetics
• Immunology
• Hepatology

Background:

• Autoimmune hepatitis (AIH) is a rare liver disease with an unknown cause.
• Genetic predisposition is suspected in AIH development.

Purpose of the Study:

• To identify genetic variants associated with AIH using a genome-wide approach.
• To understand the genetic basis of AIH and its relationship with other immune-mediated diseases.

Main Methods:

• Genome-wide association study (GWAS) in 649 Dutch AIH type 1 patients and 13,436 controls.
• Replication analysis in 451 German AIH type 1 patients and 4103 controls.
• Analysis of imputed genotypes in the major histocompatibility complex (MHC) region.

Main Results:

• A significant association was found with a variant in the MHC region (rs2187668).
• HLA-DRB1*0301 and HLA-DRB1*0401 were identified as primary and secondary susceptibility genotypes.
• Variants in SH2B3 and CARD10 were also associated with AIH risk.
• Genetic associations overlapped with those for primary sclerosing cholangitis and primary biliary cirrhosis.

Conclusions:

• GWAS identified MHC region variants, SH2B3, and CARD10 as risk factors for AIH type 1.
• These findings support a complex genetic architecture for AIH.
• A portion of AIH genetic susceptibility is shared with other immune-mediated liver diseases.