anchor.diff:  Papers that qualify for inclusion in the Catalog are identified through weekly PubMed searches.
   They then undergo two levels of curation.
   First all data, including association information for SNPs, traits and general information about the study, are extracted by one curator.
  -A second curator then performs an additional round of curation to double-check the accuracy and consistency of all the information.
  -Finally, an automated pipeline run at the NCBI performs checks for missing information, such as SNP identifiers, resolution of the citation in PubMed, existence of SNPs in dbSNP, confirmation of gene names vs. NCBI's Gene database, confirmation that the reported SNP and gene are in the same chromosomal region, as well as adding additional information such as the SNP's base pair and cytogenetic location in the current human genome reference assembly.
  -This information is then used for queries and in the production of the karyotype diagram.
  +A second curator then performs an additional round of curation to double-check the accuracy and consistency of all the information. Finally, an automated pipeline performs validation of the extracted data, see the <<mapping, Quality control and SNP mapping section>> below for more details. This information is then used for queries and in the production of the diagram.
   
   
   == Full Description of Methods
  
positive.code: 
  The ancestry is derived from the ancestry descriptors used in the publication. Country of recruitment is extracted if an author states the country of recruitment of the samples. It is not assumed from an ancestry identifier or from a cohort name. Where a country of recruitment but no ancestry is provided, published population demographic information, such as the https://www.cia.gov/library/publications/the-world-factbook/[CIA World Factbook] is consulted.
  
  ==== Quality control and SNP mapping
  
  An automated pipeline, run at the NCBI, adds additional SNP specific information associated with the rsID extracted. This information includes the SNP's base pair and cytogenetic location in the current human genome reference assembly, mapped genes and SNP function. This information is then used for queries of the search interface and in the production of the karyotype diagram. The pipeline also performs checks for consistency and missing information, such as SNP identifiers, resolution of the citation in PubMed, existence of SNPs in dbSNP, confirmation of gene names vs. NCBI's Gene database and confirmation that the reported SNP and gene are in the same chromosomal region.
  
  Additional information added by NCBI pipeline. Capitalised titles correspond to column headings in tab delimited file:
  
  * REGION: Cytogenetic region associated with rs number.
  * CHR_ID: Chromosome number associated with rs number.
  * CHR_POS: +++Chromosomal position, in base pairs, associated with rs number (dbSNP Build <span id="dbSNP">144</span>, Genome Assembly <span id="genomeBuild">GRCh38.p5</span>, NCBI).+++
  * MAPPED GENE(S): Gene(s) mapped to the strongest SNP. If the SNP is located within a gene, that gene is listed, with multiple overlapping genes separated by “;”. If the SNP is intergenic, the upstream and downstream genes are listed, separated by “-”.
  * UPSTREAM_GENE_ID: Entrez Gene ID for nearest upstream gene to rs number, if not within gene.
  * DOWNSTREAM_GENE_ID: Entrez Gene ID for nearest downstream gene to rs number, if not within gene.
  
negative.code: 
  === Eligibility criteria
  
  Studies and associations are eligible for inclusion in the NHGRI-EBI GWAS Catalog if they meet the following criteria:
  
  * Include a primary GWAS analysis, defined as array-based genotyping and analysis of 100,000+ pre-QC SNPs selected to tag variation across the genome and without regard to gene content.
  * GWAS data from published studies which are incorporated into new GWAS analyses are eligible, provided they meet the other criteria.
  