Editing Single-nucleotide polymorphism (section)

=== Disease ===
Only small amount of SNPs in the human genome may have impact on human diseases. Large scale GWAS has been done for the most important human diseases, including [[heart diseases]], [[metabolic diseases]], [[autoimmune diseases]], and [[Neurodegenerative disorder|neurodegenerative]] and [[Psychiatric disorder|psychiatric disorders]].<ref name="auto"/> Most of the SNPs with relatively large effects on these diseases have been identified. These findings have significantly improved understanding of disease pathogenesis and molecular pathways, and facilitated development of better treatment. Further GWAS with larger samples size will reveal the SNPs with relatively small effect on diseases. For common and complex diseases, such as [[type-2 diabetes]], [[rheumatoid arthritis]], and [[Alzheimer's disease]], multiple genetic factors are involved in disease etiology. In addition, gene-gene interaction and gene-environment interaction also play an important role in disease initiation and progression.<ref>{{Cite journal|last1=Musci|first1=Rashelle J.|last2=Augustinavicius|first2=Jura L.|last3=Volk|first3=Heather|date=2019-08-13|title=Gene-Environment Interactions in Psychiatry: Recent Evidence and Clinical Implications|url=|journal=Current Psychiatry Reports|volume=21|issue=9|page=81|doi=10.1007/s11920-019-1065-5|pmid=31410638|pmc=7340157|issn=1523-3812}}</ref>