Consanguinity and Inbreeding in Health and Disease in North African Populations

Abstract

North Africa is defined as the geographical region separated from the rest of the continent by the Sahara and from Europe by the Mediterranean Sea. The main demographic features of North African populations are their familial structure and high rates of familial and geographic endogamy, which have a proven impact on health, particularly the occurrence of genetic diseases, with a greater effect on the frequency and spectrum of the rarest forms of autosomal recessive genetic diseases. More than 500 different genetic diseases have been reported in this region, most of which are autosomal recessive. During the last few decades, there has been great interest in the molecular investigation of large consanguineous North African families. The development of local capacities has brought a substantial improvement in the molecular characterization of these diseases, but the genetic bases of half of them remain unknown. Diseases of known molecular etiology are characterized by their genetic and mutational heterogeneity, although some founder mutations are encountered relatively frequently. Some founder mutations are specific to a single country or a specific ethnic or geographic group, and others are shared by all North African countries or worldwide. The impact of consanguinity on common multifactorial diseases is less evident.

Clinical and genetic spectrum in 33 Egyptian families with suspected primary ciliary dyskinesia

“…The 13 mutated genes are all members of various different functional gene groups implicated in PCD . This therefore reveals a high genetic heterogeneity among PCD patients in Egypt, consistent with the high recorded rate of consanguineous marriage among Egyptians and within this study cohort (73%). The CCDC40 gene was the most frequently mutated gene within the studied cohort of families.…”

A map of copy number variations in the Tunisian population: a valuable tool for medical genomics in North Africa

“…Different approaches, including quantification of hybridization to specific oligonucleotides 13 , clone arrays 14 , direct genome sequencing 15,16 , and single-nucleotide polymorphism (SNP) array [17][18][19] , allowed to explore CNVs, thus providing their global estimates of frequencies, distribution, and functional features in large population cohorts and HapMap samples 1,2,4,16,[19][20][21][22][23][24][25][26][27][28][29] . Although medical and clinical genetic studies have been widely performed in the Arab World known to display high rates of consanguinity and endogamy, little attention has been paid to potential variations linked to health in the region 30,31 . Therefore, information related to molecular pathogenesis and knowledge of gene variants segregating in the Arab genome is lacking as well as genotype-phenotype correlation of genetic conditions for both monogenic and multifactorial diseases.…”

Genetic and reproductive consequences of consanguineous marriage in Bangladesh

“…Parental consanguinity is a predisposing factor for many multifactorial complications, including obesity, cardiovascular disorders, diabetes, and some malignancies, which may influence the reproductive outcomes [11]. However, some reports refute the impact of CM on complex and multifactorial health issues [8,20]. The estimation of the overall adverse effects of CM is highly variable and perplexing to delineate from the epidemiological context [11,15,20].…”

“…However, some reports refute the impact of CM on complex and multifactorial health issues [8,20]. The estimation of the overall adverse effects of CM is highly variable and perplexing to delineate from the epidemiological context [11,15,20].…”