ClinVar is a public archive of interpretations of clinically relevant variants, maintained by the National Center for Biotechnology Information (NCBI). It includes interpretations of both germline and somatic variants of any size, type, or genomic location. Interpretations are submitted by clinical testing laboratories, research laboratories, locus-specific databases, OMIM, GeneReviews, UniProt, expert panels, and practice guidelines. Each submission is assigned an accession number prefixed with SCV, and interpretations are aggregated by variant-condition combination, assigned an accession number prefixed with RCV. Clinical significance is calculated for the aggregate record, indicating consensus or conflict in the submitted interpretations. ClinVar uses data standards such as HGVS nomenclature for variants and MedGen identifiers for conditions. The data are available on the web as variant-specific views and can be downloaded via ftp. Programmatic access is available through NCBI's E-utilities. Future development includes providing a variant-centric XML archive and a web page for details of SCV submissions. ClinVar supports both general and advanced query interfaces. Common search terms include official gene symbols, HGVS expressions, rs numbers, and disease names. Search results are returned as variant pages. ClinVar records of interest can also be identified with NCBI's Variation Viewer. ClinVar data are also accessible via NCBI's Variation Reporter, which allows users to upload a list of genomic locations or variants of interest and returns a summary of information from dbSNP, dbVar, and ClinVar. ClinVar data are freely accessible for download via ftp. The full archive of data is the ClinVar XML file, which is produced as part of a monthly release cycle. The XML is organized around the RCV record or variant-condition relationship. Each RCV section includes the aggregate data for that RCV, as well as the full set of data (SCV) provided by each submitting group for that variant-condition. ClinVar data are also available as a VCF file. This file currently includes only ClinVar data that are also in dbSNP. An improved process to generate ClinVar's file in a more comprehensive fashion is under development. ClinVar data may also be accessed programmatically with E-utilities. ClinVar currently supports esearch, esummary, elink, and efetch. efetch can be used to access either RCV records or variation records. Future directions include developing a VariationID-centric XML and improving access to ClinVar from EHRs through Infobutton. ClinVar staff welcome feedback on the submission process, use of the website, and downloadable data. Funding for open access charge is provided by the Intramural Research Program of the National Institutes of Health, National Library of Medicine.ClinVar is a public archive of interpretations of clinically relevant variants, maintained by the National Center for Biotechnology Information (NCBI). It includes interpretations of both germline and somatic variants of any size, type, or genomic location. Interpretations are submitted by clinical testing laboratories, research laboratories, locus-specific databases, OMIM, GeneReviews, UniProt, expert panels, and practice guidelines. Each submission is assigned an accession number prefixed with SCV, and interpretations are aggregated by variant-condition combination, assigned an accession number prefixed with RCV. Clinical significance is calculated for the aggregate record, indicating consensus or conflict in the submitted interpretations. ClinVar uses data standards such as HGVS nomenclature for variants and MedGen identifiers for conditions. The data are available on the web as variant-specific views and can be downloaded via ftp. Programmatic access is available through NCBI's E-utilities. Future development includes providing a variant-centric XML archive and a web page for details of SCV submissions. ClinVar supports both general and advanced query interfaces. Common search terms include official gene symbols, HGVS expressions, rs numbers, and disease names. Search results are returned as variant pages. ClinVar records of interest can also be identified with NCBI's Variation Viewer. ClinVar data are also accessible via NCBI's Variation Reporter, which allows users to upload a list of genomic locations or variants of interest and returns a summary of information from dbSNP, dbVar, and ClinVar. ClinVar data are freely accessible for download via ftp. The full archive of data is the ClinVar XML file, which is produced as part of a monthly release cycle. The XML is organized around the RCV record or variant-condition relationship. Each RCV section includes the aggregate data for that RCV, as well as the full set of data (SCV) provided by each submitting group for that variant-condition. ClinVar data are also available as a VCF file. This file currently includes only ClinVar data that are also in dbSNP. An improved process to generate ClinVar's file in a more comprehensive fashion is under development. ClinVar data may also be accessed programmatically with E-utilities. ClinVar currently supports esearch, esummary, elink, and efetch. efetch can be used to access either RCV records or variation records. Future directions include developing a VariationID-centric XML and improving access to ClinVar from EHRs through Infobutton. ClinVar staff welcome feedback on the submission process, use of the website, and downloadable data. Funding for open access charge is provided by the Intramural Research Program of the National Institutes of Health, National Library of Medicine.