Editing Melanocytic nevus (section)

===Genetics===
[[Genes]] can influence a person's moles.

[[Dysplastic nevus syndrome]] is a largely [[hereditary]] condition that causes a person to have a large quantity of moles (often 100 or more), with some larger than normal or atypical. This often leads to a higher risk of [[melanoma]], a serious type of [[skin cancer]].<ref>{{cite journal|author=Burkhart CG|title=Dysplastic nevus declassified: even the NIH recommends elimination of confusing terminology|journal=Skinmed|volume=2|issue=1|pages=12–13|year=2003|pmid=14673319|doi=10.1111/j.1540-9740.2003.01724.x}}</ref> Dysplastic nevi are more likely than ordinary moles to become cancerous. While dysplastic nevi are common and many people have a few of these abnormal moles, having more than 50 ordinary moles also increases the risk of developing melanoma.<ref name="ncimelanoma">{{cite web|url=http://www.nci.nih.gov/cancertopics/wyntk/melanoma/page7|title=What You Need To Know About Melanoma - Melanoma: Who's at Risk?|date=January 1980|access-date=2008-05-18|publisher=[[National Cancer Institute]]}}</ref>

In the general population, a slight majority of melanomas do not form in existing moles but rather create new [[tumour|growths]] on the skin. Somewhat surprisingly, this pattern also applies to those with dysplastic nevi. These individuals are at a higher risk of melanoma occurring not only where there is an existing mole but also in areas without moles.<ref>{{cite journal|vauthors=Pope DJ, Sorahan T, Marsden JR, Ball PM, Grimley RP, Peck IM |title=Benign pigmented nevi in children. Prevalence and associated factors: the West Midlands, United Kingdom Mole Study|journal=Arch Dermatol|volume=128|issue=9|pages=1201–1206|year= 1992|pmid=1519934|doi=10.1001/archderm.128.9.1201}}</ref><ref>{{cite journal|vauthors=Goldgar DE, Cannon-Albright LA, Meyer LJ, Piepkorn MW, Zone JJ, Skolnick MH |title=Inheritance of nevus number and size in melanoma and dysplastic nevus syndrome kindreds|journal=J. Natl. Cancer Inst.|volume=83|issue=23|pages=1726–1733|year=1991|pmid=1770551|doi=10.1093/jnci/83.23.1726}}</ref> Consequently, such persons need regular examinations to check for changes in their moles and to identify any new ones.