Genetics of Skin Cancer (PDQ®): Genetics - Health Professional Information [NCI] - Melanoma
Table 7. Characteristics of Common Models for Estimating the Likelihood of aCDKN2AMutation
|Features of Model||Incorporates three different penetrance models||Uses logistic regression|
|Can input information for large families||Accounts for a number of primary melanomas in family and age of onset|
|Includes information for unaffected individuals on risk of developing melanoma|| |
|Limitations||The model has not been validated on unaffected probands.||Cannot incorporate complex pedigree structure information into the model|
| ||Does not take into account domain-specific penetrances or geographical differences in penetrance|
Clinical testing is available to identify germline mutations in CDKN2A. Multiple centers in the United States and overseas offer sequence analysis of the entire coding region, and a number of centers perform deletion and duplication analysis. For information on genetic testing laboratories, see GeneTests: Laboratory Directory.
Expert opinion regarding testing for germline mutations of CDKN2A follows two divergent schools of thought. Arguments for genetic testing include the value of identifying a cause of disease for the individual tested, the possibility of improved compliance with prevention protocols in individuals with an identified mutation, and the reassurance of a negative testing result in individuals in a mutation-carrying family. However, a negative test result in a family that does not have a known mutation is uninformative; the genetic cause of disease in these patients must still be identified. It should also be noted that members of CDKN2A mutation–carrying families who do not carry the mutation themselves remain at increased risk of melanoma. At this time, identification of a CDKN2A mutation does not affect the clinical management of the affected patient or family members. Close dermatologic follow-up of these people is indicated, regardless of genetic testing result, and pancreatic cancer screening has unclear utility, as discussed below.
If genetic testing is undertaken in this population, experts suggest that it be performed after complete genetic counseling by a qualified genetics professional who is knowledgeable about the condition.
Refer to the Psychosocial Issues in Familial Melanoma section of this summary for information about psychosocial issues related to genetic testing for melanoma risk.
Management of members of melanoma-prone families