Editing Single-nucleotide polymorphism (section)

==== Candidate gene association study ====
Candidate gene association study is commonly used in genetic study before the invention of high throughput genotyping or sequencing technologies.<ref>{{Cite journal|last1=Dong|first1=Linda M.|last2=Potter|first2=John D.|last3=White|first3=Emily|last4=Ulrich|first4=Cornelia M.|last5=Cardon|first5=Lon R.|last6=Peters|first6=Ulrike|date=2008-05-28|title=Genetic Susceptibility to Cancer|url=|journal=JAMA|volume=299|issue=20|pages=2423–2436|doi=10.1001/jama.299.20.2423|pmid=18505952|pmc=2772197|issn=0098-7484}}</ref> Candidate gene association study is to investigate limited number of pre-specified SNPs for association with diseases or clinical phenotypes or traits. So this is a hypothesis driven approach. Since only a limited number of SNPs are tested, a relatively small sample size is sufficient to detect the association. Candidate gene association approach is also commonly used to confirm findings from GWAS in independent samples.