Consanguineous marriages profile in the Tanger-Tetouan region in Morocco

Abstract

Consanguineous marriage has received a great deal of attention as a potential risk factor for many adverse health outcomes. More than a billion people in the world live in regions where 20%-50% of marriages are consanguineous. The aim of this study is to determine the frequency and types of consanguineous marriage in the region of Tanger-Tetouan in Northwest Morocco. Methods: A prospective study was conducted among a randomly selected sample of 160 university students in Tanger in 2014. All students were interviewed using a structured questionnaire. Results: The frequency of consanguineous marriages among parents of students was 39,4%, with a mean inbreeding coefficient (up to second cousins) of 0,02033. The study revealed a highly significant difference in the rates of the consanguineous marriages between the current and previous generation p< 0,001. The most common types of consanguineous marriage among current generationwere first cousin marriage, which accounts for 76,2% of all consanguineous unions, followed by first cousin once removed (11,1%) and second cousin marriage (3,2%), while 9,5% of marriages were between distant relatives. Among the previous generation, more than half of consanguineous marriages were between first cousins, whereas more the 40 % of unions were of distant relatives. The distribution of the marriages between first cousins through the generations showed that the frequency of unions between parallel cousins was superior than that of the unions between crossed cousins. It was 60, 42 % against 39, 58 % respectively to the current generation. Among the parallel first cousins, the marriage with the daughter of brother of the father was the most answered that with the daughter of sister of mother to both studied generations. The rate was 68, 97 % against 31, 03 % to the generation of the parents, then, it was 85, 71 % against 14, 29 % and 83, 33 % against 5, 88% to the generation of the paternal and maternal parents, respectively. Conclusion: Consanguineous marriage plays an important role in expression of deleterious recessive genes. Public awareness of genetic risks associated with consanguineous marriage and the importance of premarital genetic counseling is indispensable.