Other risk factors The familial cases of melanoma has resulted in many études.Dans for hereditary melanoma, we showed the autosomal dominant mode on a susceptibility gene on the short arm of chromosome 1 near the gene determining the rhesus (1p36). The relative risk is increased by 2.4 when a family member has had melanoma.
Another susceptibility gene has been identified in families affected by familial melanoma on the short arm of chromosome 9.
Hereditary factors are important in two syndromes that are familial malignant melanoma and the BK-Mole Syndrome “. Malignant melanoma families are defined by two or more melanomas in one family. They represent 1 to 6% of all melanomas.
The BK-Mole syndrome (B and K are the initials of the surnames of the first two patients in the individualized syndrome; “mole” means “naevus” in English) has been described by Clark. It is the association in several members of a family of malignant melanoma and dysplastic nevi.
The dysplastic nevi are nevi individuals by their clinical appearance and histology. This syndrome is inherited autosomal dominant with high penetrance. It represents 95% of cases of familial melanoma.
The subjects with dysplastic nevi under the BK Mole Syndrome have a risk of developing malignant melanoma assessed at 100%. History of malignant melanoma outside the familial BK Mole Syndrome represent a risk factor estimated at between 2 and 8.
Other hereditary diseases are studied. The xeroderma pigmentosum (autosomal recessive, rare, affecting one in 250 000) is characterized by a high sensitivity to the sun and a dramatic predisposition to skin cancer. The cause is a lack of repair of DNA lesions caused by UV.
The risk of melanoma would be multiplied by 2000.
One patient who already had a melanoma is more likely to submit another even if the risk is quantified in different ways. The relative risk is multiplied by 8.5 and even more when the first melanoma was diagnosed before age 40.
Some associations are common cancer (excluding melanoma may be secondary to the initial treatment of cancer).
* Skin cancer: a risk of melanoma increased by 4 to 7 (the same risk factors);
* Brain tumors, retinoblastoma: risk multiplied by 2 to 6 (same embryonic origin);
* Hodgkin’s disease (relative risk multiplied by 6 to 
and non-Hodgkin lymphoma: relative risk multiplied by 2.4;
* Chronic lymphocytic leukemia (immune deficiencies): relative risk multiplied by 6.7;
* Breast cancer: relative risk multiplied by 1.4 (which raises the problem not yet resolved the role of hormones).
Immune deficiencies appear to play a supporting role in the genesis of melanoma.
Persons who have undergone a kidney transplant have an increased risk of skin cancer and melanoma in particular. For melanoma, the relative risk is 4 to 5. Immunosuppression increases the number of naevi and melanoma.
IMMUNOSUPPRESSIVE chemotherapy treatments, congenital immune deficiencies, chronic dialysis, AIDS increases the risk of melanoma.
The puvathérapie is a theoretical risk factor that has not yet been clearly demonstrated.
The role of hormones has led to numerous studies. Skin pigmentation during pregnancy and that caused by taking estrogen-progestin pill, coupled with the impact of pregnancy on the development of melanoma has been seeking a cause and effect relationship. No evidence of hormonal action has so far been made.
Many professions have been studied without success (printers, chemists, telecommunications workers, refinery workers …) to investigate a possible factor carcinogenic chemical.
Apart from solar radiation, no environmental factor has been shown, no oncogenic virus, no effect on the micro naevi have been identified.
The topography of the lesions varies according to sex. The correspondence between the topography of lesions and areas of the body exposed to the sun is fairly clear. Men have melanomas on the trunk, especially the back, while women are more affected legs. The face and neck are affected as often in men than in women. Achieving the ears is very common in humans.