Lack of association between genetic variants in the 19q13.32 region and CHD risk in the Algerian population: a population-based nested case-control study

Background: Coronary Heart Disease (CHD) is a major cause of morbidity and mortality over the world; intermediate traits associated with CHD commonly studied can be influenced by a combination of genetic and environmental factors. Objective: We found previously significant association between three genetic polymorphisms, and the lipid profile variations in the Algerian population. Considering these findings, we therefore decided to assess the relationships between these polymorphisms and CHD risk, Methods: We performed a population-based, cross-sectional study, of 787 individuals recruited in the city of Oran, in which, a nested case-control study for MetS, T2D, HBP, obesity and CHD were performed. Subjects were genotyped for four SNP rs7412, rs429358 rs4420638 and rs439401 located in the 19q13.32 region. Results: The T allele of rs439401 confers a high risk of hypertension with an odds ratio (OR) of 1.46 (95% CI [1.12-1.9], p = 0.006) and the G allele of rs4420638 was significantly associated with a decreased risk of obesity, OR 0.48 (95% CI [0.29-0.81], p = 0.004). No associations were found for MetS, T2D and CHD. Conclusion: Although the studied genetic variants were not associated with the risk of CHD, the 19q13.32 locus was associated with some of the cardiometabolic disorders in Algerian subjects

Diagnosis of Xeroderma Pigmentosum Groups A and C by Detection of Two Prevalent Mutations in West Algerian Population: A Rapid Genotyping Tool for the Frequent XPC Mutation c.1643_1644delTG

Xeroderma pigmentosum (XP) is a rare autosomal recessive disorder. Considering that XP patients have a defect of the nucleotide excision repair (NER) pathway which enables them to repair DNA damage caused by UV light, they have an increased risk of developing skin and eyes cancers. In the present study, we investigated the involvement of the prevalent XPA and XPC genes mutations—nonsense mutation (c.682C>T, p.Arg228X) and a two-base-pair (2 bp) deletion (c.1643_1644delTG or p.Val548Ala fsX25), respectively—in 19 index cases from 19 unrelated families in the West of Algeria. For the genetic diagnosis of XPA gene, we proceeded to PCR-RFLP. For the XPC gene, we validated a routine analysis which includes a specific amplification of a short region surrounding the 2 bp deletion using a fluorescent primer and fragment sizing (GeneScan size) on a sequencing gel. Among the 19 index cases, there were 17 homozygous patients for the 2 bp deletion in the XPC gene and 2 homozygous patients carrying the nonsense XPA mutation. Finally, XPC appears to be the major disease-causing gene concerning xeroderma pigmentosum in North Africa. The use of fragment sizing is the simplest method to analyze this 2 bp deletion for the DNA samples coming from countries where the mutation c.1643_1644delTG of XPC gene is prevalent

Genetic diversity and relationships among six local cattle populations in semi-arid areas assessed by a bovine medium-density single nucleotide polymorphism data

International audienceThe local cattle populations belonging to the‘ Brune de l’Atlas’ cattle in Algeria and Morocco are potential resources in terms of genetic diversity and socioeconomic prevalence and their characterization is an essential step in any program designed to conserve genetic diversity. Our objectives were to assess the genetic diversity, the population structure and relationships among four Algerian cattle breeds, the Biskra, Cheurfa, Chelifienne and Guelmoise and of two Moroccan, the Oulmès-Zaër and Tidili by genotyping 50 309 single nucleotide polymorphism in 203 unrelated animals. A low population structure was observed across breeds with pairwise FST values ranging from 0.008 to 0.043, suggesting a high level of geneflow. These data were combined with the available data on cattle populations representative of Europe (EUT), West African taurine (WAT) and zebu (ZEB). Principle Components Analysis was carried out which revealed that the Maghrebin populations are closer to the EUT/ZEB population than to the WAT. Structure analysis confirmed this mixed origin of the Maghrebin cattle populations. We also detected the influence of zebu breeds in Cheurfa and Guelmoise populations. This study provides the first information about genetic diversity within and between Algerian and Moroccan cattle populations and gives a detailed description of their genetic structure and relationships according to their historical origins. This study revealed that several combined effects contributed to shape the genetic diversity of the six Maghrebin populations studied: (i) gene flow among local breeds, (ii) the recent introgression of European breeds in local Algerian breeds and (iii) the traditional management systems. The results of this study will primarily assist policy makers and livestock keepers to make useful decisions for improvement of genetic resources while ensuring the preservation and conservation of local breeds in Algeria and Morocco

The TCF7L2 rs7903146 polymorphism, dietary intakes and type 2 diabetes risk in an Algerian population.

International audienceBackgroundThe transcription factor 7-like 2 (TCF7L2) gene is the most significant genetic risk factor for type 2 diabetes (T2D). Association analyses were performed on participants (n¿=¿751, aged between 30 and 64) in the ISOR population-based study in the city of Oran. Dietary intakes were estimated using a weekly food frequency questionnaire.ResultsThe T allele of the rs7903146 single nucleotide polymorphism (SNP) was associated with lower body weight (p¿=¿0.02), lower BMI (p¿=¿0.009), lower waist circumference (p¿=¿0.01) and a lower waist-to-hip ratio (p¿=¿0.02). The T allele was associated with a significantly higher risk of T2D (odds ratio (OR) (95% confidence interval)¿=¿1.55 (1.09¿2.20), p¿=¿0.01) and this association was independent of BMI. When considering the T2D risk, there were nominal interactions between the rs7903146 SNP and dessert (p¿=¿0.05) and milk intakes (p¿=¿0.01). The T2D risk was greater in T allele carriers with high dessert and milk intakes (OR¿=¿2.61 (1.51-4.52), p¿=¿0.0006, and 2.46 (1.47-4.12), p¿=¿0.0006, respectively). In subjects with a high dessert intake, the T allele was also associated with higher fasting plasma glucose concentrations (4.89¿±¿0.46 mmol/L in TT subjects, 4.72¿±¿0.48 mmol/L in CT subjects and 4.78¿±¿0.51 mmol/L in CC subjects; p¿=¿0.03).ConclusionsThe T allele of the rs7903146 SNP is associated with a significantly higher risk of T2D in an Algerian population. This association was further strengthened by a high dessert intake, suggesting that gene-diet interactions increase the T2D risk