Biochemical and Biophysical Research Communications
The analysis of three markers flanking GJB2 gene suggests a single origin of the most common 35delG mutation in the Moroccan population
Section snippets
Materials and methods
Subject. Thirty unrelated deaf patients with NSHL homozygous for the 35delG mutation and 165 unrelated control individuals devoid of this mutation were enrolled in this study. All subjects were originating from various regions of Morocco. Informed consent was obtained from all participants or their parents.
Microsatellite genotyping. The DNA was extracted using a phenol chloroform method. Three STR markers, D13S141, D13S175, and D13S143, mapping on chromosome 13 regions flanking the GJB2 gene,
Results
In order to test the origin of 35delG mutation, we genotyped three STR markers, D13S141, D13S175, and D13S143, flanking the GJB2 gene, in 60 35delG mutated and 330 normal chromosomes. The distribution of genotypes for each marker was in accordance with the Hardy–Weinberg Equilibrium in the normal population, with p-values of 0.968, 0.940, and 0.769 for D13S141, D13S175, and D13S143, respectively. Conversely, in the deaf patient group, all markers showed a significant deviation from
Discussion
The 35delG is the most frequent GJB2 mutation in Euro-Mediterranean patients with autosomal recessive NSHL, and also present at high frequency in general populations [7], [18], [19]. The same situation was reported in the Moroccan population in which the carrier frequency was estimated to be 2.65% [20], [21]. The high carrier rates of the 35delG mutation observed in the Caucasian population are generally attributed to a founder effect, based on haplotype conservation of closely linked markers
Acknowledgments
We are grateful to the families and associations for their cooperation and support. We also thank Dr. Guy LENAERS (Institut des Neurosciences de Montpellier, France) for critical reading of the manuscript.
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Update of the spectrum of GJB2 gene mutations in 152 Moroccan families with autosomal recessive nonsyndromic hearing loss
2016, European Journal of Medical GeneticsCitation Excerpt :Some studies have raised the possibility of a founder effect of an ancestral mutation expanded throughout the Mediterranean shore. In the Moroccan population, the estimated age of the c.35delG mutation was 2700 years ago (135 generations) (Abidi et al., 2008a). Conversely, the c.35delG mutation is absent in Japanese patients (Fuse et al., 1999; Abe et al., 2000).