Low Level of Consanguinity in Moroccan Families at High Risk of Breast Cancer

Abstract

Background: Breast cancer is worldwide the most common cancer in women and is a major public health problem. Genes with high or low penetrance are now clearly implicated in the onset of breast cancer, mostly the BRCA genes. All women in families at high risk of breast cancer do not develop tumours, even when they carry the familial mutation, suggesting the existence of genetic and environmental protective factors. Several studies have shown that consanguinity is linked to a decreased or an increased risk of breast cancer, but to the best of our knowledge, there is no study concerning the association between consanguinity and the occurrence of tumours in women with high risk of breast cancer. The objective of this study was to examine whether parental consanguinity in families with genetic predisposition to breast cancer affect the risk of siblings for having this cancer. Materials and Methods: Over a six-year period, 72 different patients with a histological diagnosis of breast or ovarian cancer from 42 families were recruited for genetic counselling to the Department of Medical Genetics, Rabat. Consanguinity rate was determined in cases and compared to the consanguinity rate in the Moroccan general population. Results: Consanguinity rates were 9.72% in patients and 15.3% in controls, but the difference was statistically not significant (p>0.001) and the mean coefficient of consanguinity was lower in breast cancer patients (0.0034) than in controls (0.0065). Conclusions: Despite the relatively small sample size of the current study, our results suggest that parental consanguinity in Moroccan women might not be associated with an altered risk of breast cancer. Large scale studies should be carried out to confirm our results and to develop public health programs.

Prevalence of Hereditary Cancer Susceptibility Syndromes (HCSS) in Acute Lymphoblastic Leukemia (ALL): A Cross-Sectional Study in a Highly Consanguineous Population.

“…The results showed that age at the diagnosis of disease, hepatospleenomegaly and subtype of ALL was comparable among consanguineous and non-consanguineous patients however consanguineous showed signi cantly protective impact age at diagnosis of disease (Table 2). This is in concordance with the previous studies performed in highly consanguineous populations of Middle East that suggests that consanguinity confers protective effect to the development of the adult cancers at an early age (26)(27)(28). In the previous studies, different germ line genetic variations have been associated with the chemotherapy related cardiotoxicity (29,30).…”

Age-Standardized Incidence Rates for Leukemia Associated With Consanguineous Marriages in 68 Countries, an Ecological Study

“…29 – 32 However, several studies had shown that countries with high consanguinity demonstrate lower age-standardized mortality rates and incidence in breast cancer,. 15 , 33 , 34 …”

First application of next-generation sequencing in Moroccan breast/ovarian cancer families and report of a novel frameshift mutation of the BRCA1 gene

“…The mutational spectrum of BRCA1/2 in the Moroccan population is becoming partially characterised thanks to local genetic centers, who have developed oncogenetic consultations for familial forms of breast and ovarian cancers and performed molecular analyses of BRCA genes using the conventional individual exon-by-exon Sanger sequencing (10,13,14,16,17). Thus, several mutations in two particular genes have been reported in the Moroccan National Genetic Database (http:// ethnos.findbase.org/home-ma).…”