Inheritance in breast and ovarian tumors

The majority of breast and ovarian cancers have an incidence of 11% and 1-2%, over the life span of population. Only a small but significant percentage of the tumors of these organs, estimated to be between 7 and 10%, arise due to the presence from birth of germline genetic mutations of DNA that can be transmitted to children (hereditary tumors).
This means that we transmit the mutation (not the tumor!!) and the predisposition to get sick.
The carrier of the genetic defect can be both male and female; the children have a 50% chance of inheriting the gene mutation.

Main clinical features:
• Age of onset much younger than the general population: before 36 years for the breast and before 45 for the ovary
• Appearance in several members of the family belonging to different generations
• Increased frequency of bilateral breast cancer
• Breast cancer in male subjects
• Evidence of ovarian cancer cases in the family
• Mammary and ovarian cancer in the same person

BRCA1 and BRCA2 mutations
To date, mutations on BRCA1 and BRCA2 genes have been associated with breast and ovarian cancer: genes able to control cell growth and replication mechanisms (tumor suppressors). The alteration of these genes leads to the suppression of their function, then to the uncontrolled cell growth and, in the long run, to the formation of the tumor.


The Genetics of Melanoma

Melanoma is not a condition that can be inherited. However, the predisposition to melanoma is hereditary. The genetic susceptibility to melanoma occurs when specific genetic mutations have passed from generation to generation. Many people, however, who inherit this predisposition, may also never develop melanoma in their lifetime.

If there is a family history of melanoma, what is the risk?
If a person has a first-degree relative with melanoma, his risk of developing melanoma grows two or three times compared to the rest of the population. The risk is extremely higher (30-70 times) if there are more than one first-degree relatives affected by melanoma.

Which genetic mutations increase the risk of melanoma?
There is an increasing number of genes thought to be associated with an increased risk of melanoma. However, more research is needed to better understand how these genes affect the risk of developing melanoma.
Mutations in at least three genes have been linked to hereditary melanoma. Families with mutations in these genes may have numerous dysplastic nevi. The presence of numerous dysplastic nevi is also sometimes called neural atypical multiple syndrome (FAMMM), or dysplastic nevus syndrome (DNS) or atypical nevi syndrome (AMS).