The Clinical Genome Resource (ClinGen) Familial Hypercholesterolemia Variant Curation Expert Panel consensus...

Area of Science:

• Genetics
• Molecular Pathology
• Clinical Diagnostics

Background:

• Established American College of Medical Genetics and Genomics (ACMG) and Association for Molecular Pathology (AMP) guidelines (2015) standardize variant classification in Mendelian disorders.
• Familial Hypercholesterolemia (FH) requires accurate variant classification for effective patient management.
• Over 2300 unique variants are associated with the LDLR gene, a primary cause of FH.

Purpose of the Study:

• To optimize the existing ACMG/AMP framework for disease-specific variant classification in FH.
• To develop consensus recommendations for classifying variants in the LDLR gene.

Main Methods:

• A multidisciplinary FH Variant Curation Expert Panel convened to modify ACMG/AMP guidelines.
• Methods included in-person meetings, email, conference calls, iterative development, pilot testing, and expert debate.
• Consensus was reached on specific modifications for LDLR variant classification.

Main Results:

• Modified guidelines include altered population frequency thresholds.
• Specific criteria were defined for loss-of-function variants and functional studies.
• Refined specifications for cosegregation analysis and in silico prediction tools were established.

Conclusions:

• These LDLR-specific modifications provide a harmonized, evidence-based approach to variant classification.
• Implementation as a new standard will enhance the accuracy of LDLR variant classification globally.
• Improved classification will ultimately lead to better patient care for individuals with FH.