Trisomie 21 : Étude comparative Algérie, Tunisie, Maroc et France

Abstract

Trisomy 21 or Down syndrome is a congenital disease caused by abnormal cell division which results in an increase in the total or partial copies of chromosome 21. This additional genetic material causes developmental changes and birth defects, accidental unpredictable resulting in mental retardation. And a more increased probability of certain diseases (GRECO, 2010). Unfortunately, we have not studied any sample and give precise results on the subject. Where our study includes a comparative study of the population with Down's syndrome in four countries: Algeria, Tunisia, Morocco and France. but in the theoretical part, we mentioned risk factors associated with Down's syndrome, the results of this study showed that the prevalence of births with Down's syndrome increases exponentially with maternal age, The mean age of the mother at conception of children with Down's syndrome was 35 years old. In Algeria, Tunisia and morocco, the population affected by trisomy 21 lacks studies, unfortunately. And in France despite the awareness of this disease and the diagnosis and monitoring of a pregnancy, and offering screening for trisomy 21. but the down syndrome remains the most common type of trisomy in newborns, The majority of children with Down's syndrome suffer from obesity, heart disease, thyroid problems .The genetic study showed that all the cases studied present a free and homogeneous trisomy 21 (47, XX, + 21; 47, XY, + 21), the karyotypes of the parents were normal (46, XX; 46, XY). . The increase in maternal age considered the most risk factor relates to Down's syndrome and inbreeding and father's age, so we can say that inbreeding reduces the maternal age can have children with a disease genetic, but it appears to have no direct significant effect and is not statistically significant.