Allelic and haplotypic data of MHC class II Alu insertions in Ngazidja (Comoros archipelago) and insight on its historical biology.

This study aimed to analyse, for the first time, five MHC class II polymorphic Alu insertions in a population with a strong Sub-Saharan African genetic background: the Ngazidja islanders and compare its allelic and haplotypic data with Worldwide populations. The genotyping was performed in 80 individuals, using simple PCR and agarose gel electrophoresis methods. Allele and haplotype frequencies, genetic diversity, Hardy-Weinberg equilibrium deviations, normalized deviate of homozygotes and pairwise linkage disequilibrium were estimated. The phylogenetic analyses included the available population data. In Ngazidja, the MHC class II Alu insertion frequencies ranged from 0.119 for AluORF10 to 0.588 for AluDPB2. Concerning haplotypes, the most predominant were the ones with only the AluDPB2 insertion allele (AluDPB2*2-AluDQA2*1-AluDQA1*1-AluDRB1*1-AluORF10*1), followed by the theoretical ancestral haplotype with no Alu insertions (AluDPB2*1-AluDQA2*1-AluDQA1*1-AluDRB1*1-AluORF10*1) and finally the haplotype with the AluDPB2 and AluDQA1 Alu insertions (AluDPB2*2-AluDQA2*1-AluDQA1*2-AluDRB1*1-AluORF10*1) with frequencies of 19.2%, 15% and 12.9%, respectively. In the phylogenetic analyses, our results indicate that the Ngazidja people are genetically differentiated from the other populations of the analysis; we found also a new haplotype that can be probably characteristic of Sub-Saharans and finally confirm the usefulness of these markers as genetic and evolutionary tools for studying genetic variations among populations of different origins.

Alu elements within the human major histocompatibility class I region in the Comoros Islands: genetic variation and population relationships.

Background: Alu elements are attractive markers for population genetics, disease, forensics and paternity analyses, due to their particular characteristics. Five polymorphic Alu insertions within the MHC class I region have been little examined in human populations. Aim: The analysis of the genetic diversity of autochthonous Comorians from the three major islands of the archipelago by these polymorphic MHC Alus and to assess their relationships together and with other populations. Subjects and methods: Two hundred and fifty-seven unrelated participants from the Comoros archipelago, Grande Comore (86), Anjouan (93) and Moheli (78), were examined for five MHC Alu insertions. The data were analysed for intra- and inter-population genetic variation. Results: All MHC Alu were polymorphic in the three samples and only one significant differentiation was observed between Anjouan and Moheli. According to the MDS and AMOVA results, the populations included in the inter-population analyses were grouped in three major clusters according to their genetic ancestry. The haplotype diversity showed by the Comorians is higher than in previously studied African populations and occupies an intermediate position between African and Asian clusters. Conclusion: MHC Alu insertions are useful markers to study micro-geographical genetic variations. Using these polymorphisms, new insights have been obtained about the biological history and evolution of the Comoros.

COVID-19 pandemic: Effects of national lockdown on the state of health of patients with type 2 diabetes mellitus in a Moroccan population.

BACKGROUND: The complete lockdown caused by the COVID-19 pandemic had imposed a new behavior and lifestyle especially in terms of diet, physical activity, and the management of patients with chronic diseases. AIM: The present study aimed to analyze the impact of lockdown on the monitoring and care of type 2 diabetes mellitus (T2DM) patients in a Moroccan population from the Doukkala region. SUBJECTS AND METHODS: We conducted a retrospective observational study including 121 T2DM patients recruited from the Diabetes Diagnosis and Treatment Center of El Jadida city. Demographic, anthropometric, and biochemical data of our T2DM patients were recorded before and after lockdown that lasted 82 days. All patients have signed an informed consent after being informed about the purely scientific aims of the study. RESULTS: Our sample involved 84 women and 37 men with an age average of 57.31 ± 0.91 years. The effects of lockdown were more marked in women than in men: women showed a significant tendency to gain weight (from 78.13 ± 1.36 kg to 81.80 ± 1.45 kg; p-value < 0.000), that impacted the body mass index (p-value < 0.000); they also showed significant increases in HbA1c values (p-value = 0.001), significant decrease in systolic blood pressure (p-value = 0.0302) and a surprising increase in high-density lipoprotein cholesterol (p-value = 0.0132). The prevalence of metabolic syndrome in the women sample increased from 46.4% to 54.8% after the lockdown. In men, the negative effect of lockdown was observed only in HbA1c that values increased significantly from 8.66 ± 0.21% to 9.51 ± 0.25% (p-value = 0.0127). CONCLUSION: Our results reveal that lockdown had impacted negatively the health status of T2DM patients, especially women. We suggest an urgent development of programs aiming to improve the hygiene of life and to reduce the impact of future crises on patients suffering chronic diseases such as T2DM.