How are genetic variants interpreted under ACMG guidelines?

How are genetic variants interpreted under ACMG guidelines?

• A. They are categorized as pathogenic, likely pathogenic, VUS, likely benign, or benign based on evidence strength.
• B. They are categorized as positive or negative.
• C. They are interpreted solely based on family history.
• D. They are not classified.

Answer: (A)

Under ACMG guidelines, genetic variants are interpreted using a five-tier classification that reflects how likely the variant is to cause disease: pathogenic, likely pathogenic, variant of uncertain significance, likely benign, or benign. This framework isn’t based on a single clue; it combines multiple lines of evidence—population frequency, computational predictions, functional studies, segregation in families, de novo occurrence, and other data. Each piece of evidence is weighted (very strong, strong, moderate, supporting for pathogenic; or standalone/strong for benign), and the combined evidence determines the final category. This standardization helps labs report consistently and guides clinical decisions. For example, a loss-of-function variant in a gene with known haploinsufficiency and very rare population frequency, supported by functional data, would be deemed pathogenic or likely pathogenic. Conversely, a common variant with no disease association would be categorized as benign. If evidence is insufficient or conflicting, the variant is labeled as a variant of uncertain significance.

Under ACMG guidelines, genetic variants are interpreted using a five-tier classification that reflects how likely the variant is to cause disease: pathogenic, likely pathogenic, variant of uncertain significance, likely benign, or benign. This framework isn’t based on a single clue; it combines multiple lines of evidence—population frequency, computational predictions, functional studies, segregation in families, de novo occurrence, and other data. Each piece of evidence is weighted (very strong, strong, moderate, supporting for pathogenic; or standalone/strong for benign), and the combined evidence determines the final category. This standardization helps labs report consistently and guides clinical decisions. For example, a loss-of-function variant in a gene with known haploinsufficiency and very rare population frequency, supported by functional data, would be deemed pathogenic or likely pathogenic. Conversely, a common variant with no disease association would be categorized as benign. If evidence is insufficient or conflicting, the variant is labeled as a variant of uncertain significance.