public genetic variant database · BEGINNER LESSON
ClinVar
ClinVar is a public archive of human genetic variants. It stores submitted interpretations of what a variant means for disease association or drug response, and it can also show the evidence used for those interpretations.
What ClinVar is
ClinVar is a publicly accessible database of human genetic variations. The main thing it records is a variant classification: for example, whether a change is considered benign, likely benign, uncertain significance, likely pathogenic, or pathogenic, and in some cases whether it relates to drug response. It also may store the associated disease and the evidence used by submitters. NCBI (National Center for Biotechnology Information) calculates an aggregate classification from submitted data in some records.
[2] The Clinical Pharmacogenetics Implementation Consortium’s Consensus-Based Framework for Assigning Allele Function [3] Exploring penetrance of clinically relevant variants in over 800,000 humans from the Genome Aggregation Database
How the classifications are made
ClinVar collects submissions mainly from diagnostic laboratories and some research studies. Multiple submitters can contribute to the same variant, and their evidence may be shared. For many variants, submitters use standards from ACMG (American College of Medical Genetics and Genomics) and AMP (Association for Molecular Pathology). Some records also show expert-panel curation, where a specialist group reviews the evidence. For example, one HRAS variant was marked benign for a Noonan-related syndrome because the record included population frequency, unaffected individuals, intact protein function, and lack of disease segregation.
[2] The Clinical Pharmacogenetics Implementation Consortium’s Consensus-Based Framework for Assigning Allele Function [1] VCV000040431.47 - ClinVar - NCBI - NIH
What the labels mean in practice
A classification is not the same as a direct measurement of disease. It is an interpretation built from observations such as how common a variant is in a population, whether it appears in affected or unaffected people, and whether lab or computational evidence supports a biological effect. For some drug-related alleles, other resources may use a tiered evidence system that assigns function from no evidence up to definitive evidence. ClinVar is one source that can be used when a gene is not curated elsewhere.
[1] VCV000040431.47 - ClinVar - NCBI - NIH [2] The Clinical Pharmacogenetics Implementation Consortium’s Consensus-Based Framework for Assigning Allele Function
Limitations
ClinVar is a crowd-sourced, voluntary archive, so records can be outdated or incorrect. Many variants have only one submitter, which lowers confidence. Some apparent variant signals in population data can come from sequencing artifacts, somatic variation, or biology that makes a variant less disruptive than expected. Also, a label such as not loss of function does not automatically tell you whether a variant is benign or pathogenic overall.
Why it matters
ClinVar is useful because it centralizes variant interpretations and the evidence behind them, making it easier to compare submissions and study how often variants are classified the same way across sources. It supports both disease genetics and some drug-response interpretation, but its results should always be read as evidence-based judgments rather than final proof.
[2] The Clinical Pharmacogenetics Implementation Consortium’s Consensus-Based Framework for Assigning Allele Function [3] Exploring penetrance of clinically relevant variants in over 800,000 humans from the Genome Aggregation Database
SEE THE IDEA
How ClinVar records a variant
A laboratory or study submits a human genetic variant and a classification.
Submitter evidence may include population frequency, segregation, function, or expert review.
NCBI stores the submissions and may calculate an aggregate classification.
Researchers or clinicians compare submissions, evidence, and disagreements.
Submissions and evidence flow into a shared record, and the record is then used for comparison and interpretation.
ClinVar connects submitted evidence to a public variant classification record, but it does not replace careful review of the underlying data.
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Sources and further reading
This general lesson was generated from public source material. It explains a concept; it does not interpret a private paper or provide medical advice.