Qatar's genetic counseling landscape: Current insights and future prospects.

Genetic counseling is a dynamic and rapidly growing field. In Qatar, the significance of genetic counseling is underscored by the distinctive demographic characteristics of the population, including elevated rates of consanguinity and larger family sizes, contributing to the increased incidence of many genetic conditions. This emphasizes the crucial role of genetic counseling in addressing the specific needs of the community.

The genetic basis and the diagnostic yield of genetic testing related to nonsyndromic hearing loss in Qatar.

Hearing loss is the most predominant sensory defect occurring in pediatrics, of which, 66% cases are attributed to genetic factors. The prevalence of hereditary hearing loss increases in consanguineous populations, and the prevalence of hearing loss in Qatar is 5.2%.

Prevalence and Genotype-Phenotype Correlation of Lynch Syndrome in a Selected High-Risk Cohort from Qatar's Population.

Lynch syndrome (LS) is the most common cause of hereditary colorectal cancers (CRC) and is associated with an increased risk for ovarian and endometrial cancers. There is lack of knowledge on the epidemiology of LS in the non-Caucasian populations especially in Qatar. The aim of this retrospective study is to explore the prevalence of LS in a selected high-risk cohort in the State of Qatar in addition to investigating the frequency and genotype-phenotype correlation associated with mismatch repair genes pathogenic variants.

Investigation of Genetic Causes in Patients with Congenital Heart Disease in Qatar: Findings from the Sidra Cardiac Registry.

Congenital heart disease (CHD) is one of the most common forms of birth defects worldwide, with a prevalence of 1-2% in newborns. CHD is a multifactorial disease partially caused by genetic defects, including chromosomal abnormalities and single gene mutations. Here, we describe the Sidra Cardiac Registry, which includes 52 families and a total of 178 individuals, and investigate the genetic etiology of CHD in Qatar.

Insights into the Middle Eastern paternal genetic pool in Tunisia: high prevalence of T-M70 haplogroup in an Arab population.

To obtain refreshed insights into the paternal lineages of Tunisian populations, Y-chromosome diversity was assessed in two populations belonging to an Arab genealogical lineage, Kairouan and Wesletia, as well as in four Tunisian Andalusian populations, Testour, Slouguia, Qalaat-El-Andalous and El Alia. The Arabs from Kairouan revealed 73.47% of E-M81 and close affinities with Berber groups, indicating they are likely arabized Berbers, clearly differentiated from the Arabs from Wesletia, who harbored the highest frequency (71.

Usefulness of COMT gene polymorphisms in North African populations.

The COMT gene encodes for catechol-O-methyl-transferase, an enzyme playing a major role in regulation of synaptic catecholamine neurotransmitters. Investigating 4 markers of the COMT gene (rs2020917, rs4818, rs4680, rs9332377) in 6 Tunisian populations and a pool of Libyans. Our objective was to determine the distribution of allelic, genotypic and haplotypic frequencies by comparison to other populations of the 1000 genomes project and 59 populations from the Kidd Lab dataset.

Ancient and recent Middle Eastern maternal genetic contribution to North Africa as viewed by mtDNA diversity in Tunisian Arab populations.

Objectives: Through previous mitochondrial DNA studies, the Middle Eastern maternal genetic contribution to Tunisian populations appears limited. In fact, most of the studied communities were cosmopolitan, or of Berber or Andalusian origin. To provide genetic evidence for the actual contribution of Middle Eastern mtDNA lineages to Tunisia, we focused on two Arab speaking populations from Kairouan and Wesletia known to belong to an Arab genealogical lineage.

The Orientalisation of North Africa: New hints from the study of autosomal STRs in an Arab population.

Background: Recent genomic analyses suggest that the current North African gene pool was mainly influenced by population flow coming from the East that altered the genetic structure of autochthonous Berber populations. Such genetic flow has not been extensively addressed yet using North African populations of Middle-eastern origin as reference.

Aim: To discern the Middle-eastern component in the genetic background of Tunisian Arabs and evaluate the extent of gene flow from the Middle East into North African autochthonous Berber populations.

Evaluating a subset of ancestry informative SNPs for discriminating among Southwest Asian and circum-Mediterranean populations.

Many different published sets of single nucleotide polymorphisms (SNPs) and/or insertion-deletion polymorphisms (InDels) can serve as ancestry informative markers (AIMs) to distinguish among continental regions of the world. For a focus on Southwest Asian ancestry we chose to start with the Kidd Lab panel of 55 ancestry-informative SNPs (AISNPs) because it already provided good global reference data (FROG-kb: frog.med.

Wild-type genotypes of BRCA1 gene SNPs combined with micro-RNA over-expression in mammary tissue leading to familial breast cancer with an increased risk of distant metastases' occurrence.

Germ line deleterious mutations of BRCA1 gene are not the unique factor that could inactivate BRCA1 protein which leads to familial breast cancer onset with distant metastases' occurrence. The present research explores the role that could be assigned to BRCA1 SNPs to inactivate BRCA1 protein and therefore to the occurrence of familial breast cancer with an increased risk of distant metastases' occurrence. The presence or the absence of BRCA1 protein was first analyzed by applying the immunohistochemistry technique to the tumors with sporadic and familial breast cancer.

First report of molecular diagnosis of Tunisian hemophiliacs A: identification of 8 novel causative mutations.

Introduction: Hemophilia A is an X linked recessive hemorrhagic disorder caused by mutations in the F8 gene that lead to qualitative and/or quantitative deficiencies of coagulation factor VIII (FVIII). Molecular diagnosis of hemophilia A is challenging because of the high number of different causative mutations that are distributed throughout the large F8 gene. Molecular studies of these mutations are essential in order to reinforce our understanding of their pathogenic effect responsible for the disorder.

Allele frequencies for 15 autosomal STR markers in the Libyan population.

Background: Until recently Libya remained the only state of the Maghreb without genetic evolution investigations of the genetic landscape of its population. Apart from some studies of Libyan Jews and Libyan Tuareg, only two recent investigations, based on autosomal ancestry informative SNP and mitochondrial DNA markers, have concerned the general Libyan population.

Aim: The present work is the first to describe STR markers polymorphism in the general Libyan population in order to contribute to the analysis of its genetic diversity for forensic purposes.

Genetic structure of Tunisian ethnic groups revealed by paternal lineages.

Tunisia has experienced a variety of human migrations that have modeled the myriad cultural groups inhabiting the area. Both Arabic and Berber-speaking populations live in Tunisia. Berbers are commonly considered as in situ descendants of peoples who settled roughly in Palaeolithic times, and posterior demographic events such as the arrival of the Neolithic, the Arab migrations, and the expulsion of the "Moors" from Spain, had a strong cultural influence.

Mitochondrial DNA and Y-chromosome microstructure in Tunisia.

Mitochondrial DNA (mtDNA) and Y-chromosome variation has been studied in Bou Omrane and Bou Saâd, two Tunisian Berber populations. In spite of their close geographic proximity, genetic distances between them were high and significant with both uniparental markers. A global analysis, including all previously studied Tunisian samples, confirmed the existence of a high female and male population structure in this country.

Substructure of a Tunisian Berber population as inferred from 15 autosomal short tandem repeat loci.

Currently, language and cultural practices are the only criteria to distinguish between Berber autochthonous Tunisian populations. To evaluate these populations' possible genetic structure and differentiation, we have analyzed 15 autosomal short tandem repeat loci (CSF1PO, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D21S11, FGA, TH01, TPOX, VWA, D2S1338, and D19S433) in three southern Tunisian Berber groups: Sened, Matmata, and Chenini-Douiret. The exact test of population differentiation based on allele frequencies at the 15 loci shows significant P values at 7 loci between Chenini-Douiret and both Sened and Matmata, whereas just 5 loci show significant P values between Sened and Matmata.

Data for Y-chromosome haplotypes defined by 17 STRs (AmpFLSTR Yfiler) in two Tunisian Berber communities.

The 17 Y-chromosomal short tandem repeats (STRs) included in the AmpFLSTR Yfiler PCR Amplification Kit (AB Applied Biosystems) (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635 and GATA H4) were typed in two Berber communities, a small village (Takrouna) and a town (Sejenane), from North Tunisia. As expected, diversity was higher in the town, even when compared with a pool of three small Berber communities, probably due to the combination of different founder effects and genetic drifts operating in the small villages.

Y-chromosomal STR haplotypes in three ethnic groups and one cosmopolitan population from Tunisia.

The 11 Y-chromosomal short tandem repeats (STRs) included in the Promega Corporation PowerPlex Y System (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385, DYS437, DYS438 and DYS439) were typed in three ethnic groups ("Andalusians", Berber and Arab) and one cosmopolitan population (Tunis) from Tunisia, summing up 247 individuals, and 139 different haplotypes. Focusing the analysis on the seven Y-STRs of the YHRD Minimal Haplotype Core (DYS385 excepted), "Andalusians" showed no differences from the Cosmopolitan and the Arab samples previously published (our Arab sample presented an extremely low haplotype diversity), but were different from the Berbers. The Berbers from Tunisia were not different from those from Morocco.

Distribution of Y chromosome lineages in Jerba island population.

We have analysed Y chromosome polymorphism on six STR markers (DYS19, DYS389I, DYS390, DYS391, DYS392, and DYS393) and eight classical UEP markers (SRY10831a, YAP, SRY4064, M2, 92R7, M9, SRY2627 and 12f2) in three distinct ethnical, linguistic and cultural groups of Jerba island (Berbers, Arabs and a Jerban group of Sub-Saharan origin). Fst genetic distance and principal co-ordinate analysis based on STR haplotype frequencies, showed a genetic differentiation between the three Jerban groups and a genetic relationship between Jerban Berbers and Mozabites (a well defined Berber group in Algeria). Compound use of UEP and STR markers have increased discriminatory capacity.