Disease-specific ACMG/AMP guidelines improve sequence variant interpretation for hearing loss

Purpose: The ClinGen Variant Curation Expert Panels (VCEPS) provide disease-specific rules for accurate variant interpretation. Using hearing loss-specific American College of Medical Genetics/Association for Molecular Pathology (HL-specific ACMG/AMP) guidelines, the ClinGen Hearing Loss VCEP (HL VCEP) illustrates the utility of expert specifications in resolving conflicting variant interpretations. Methods: A total of 157 variants across nine hearing loss genes were curated and submitted to ClinVar by the HL VCEP. The curation process consisted of collecting published and unpublished data for each variant by biocurators, followed by bi-monthly meetings of an expert curation subgroup that reviewed all evidence and applied the HL-specific ACMG/AMP guidelines to reach a final classification. Results: Before expert curation, 75% (117/157) of variants had single or multiple VUS submissions (17/157) or had conflicting interpretations in ClinVar (100/157). After applying the HL-specific ACMG/AMP guidelines, 24% (4/17) of VUS variants and 69% (69/100) of discordant variants were resolved into Benign (B), Likely Benign (LB), Likely Pathogenic (LP), or Pathogenic (P). Overall, 70% (109/157) variants had unambiguous classifications (B, LB, LP, P). We quantify the contribution of the HL-specified ACMG/AMP codes to variant interpretation. Conclusion: Expert specification and application of the HL-specific ACMG/AMP guidelines effectively resolved discordant interpretations in ClinVar. This study supports the utility of ClinGen VCEPs in helping the community move towards more consistent variant interpretations, which will improve the care of patients with genetic disorders.