Genetic testing and first presymptomatic diagnosis in Moroccan families at high risk for breast/ovarian cancer.

ABSTRACT

Germline mutations in the BRCA1 and BRCA2 genes highly predispose to breast and ovarian cancers and are responsible for a substantial proportion of familial breast and ovarian cancers. No female individuals from families from Morocco affected by breast cancer with mutations of these genes have previously been reported, and clinicians in Morocco are unaccustomed to dealing with healthy female individuals carrying mutations in the BRCA genes. This study aimed to report the initial experience of a group of Moroccan investigators carrying out predictive genetic testing to detect a known familial mutation in healthy Moroccan females with a high risk of developing breast cancer and to introduce supervision of these asymptomatic female carriers as a new approach in the prevention and early diagnosis of breast and ovarian cancers in Morocco. Presymptomatic diagnosis was carried out using DNA genetic testing in 5 healthy Moroccan female individuals from three families with an elevated risk of developing breast cancer. These are the first Moroccan families reported to be affected by breast cancers associated with BRCA mutations. Presymptomatic diagnosis was carried out for breast cancer in 5 female individuals from three Moroccan families with BRCA mutations. Two of the families are the first reported incidence of the founder mutation Ashkenazi BRCA1-185_186delAG in Moroccan patients. The third family carried the known BRCA2 mutation c.5073dupA/p.trp1692metfsX3. We tested the presence of these mutations in 5 asymptomatic healthy females from the three families. Two sisters from family 1 carried the BRCA1-185_186delAG mutation, whereas the third female individual from family 2 carried the c.5073dupA/p.trp1692metfsX3 mutation. However, one healthy female individual and her mother from family 3 did not carry the familial mutation of the BRCA1 gene. This study found BRCA mutations in three asymptomatic subjects, suggesting that this is the first step towards the development of persistent medical monitoring of females from families with a history of breast and ovarian cancers. Consequently, it is crucial for oncologists in Morocco to initiate the supervision of healthy female individuals with genetic defects which may lead to hereditary cancers.