Polymorphism (rs7096206 and rs7095891) in the MBL2 gene in populations of the Far North

Background. Bronchopulmonary diseases, including bronchial asthma (BA), are a significant health concern among the indigenous populations of the Far North. Deficiency of mannose-binding lectin (MBL), which participates in the opsonization of respiratory pathogens, is associated with infections that contribute to BA exacerbations. Single nucleotide polymorphisms (SNPs) in the MBL2 gene are known risk factors for multifactorial pathologies.

Aim: 1) to perform a comparative analysis of the genotype and allele frequencies of MBL2 polymorphisms rs7096206 and rs7095891 in the Nenets and Dolgan-Nganasan populations relative to the Russian population; 2) to evaluate the association of these polymorphisms with bronchial asthma in the Russian population (case-control study).

Methods. The study samples included: newborns from the Nenets (n=261) and Dolgan-Nganasan (n=104) populations, Russian children with BA (n=400), and Russian children without asthma or chronic diseases (n=229). Genotyping was performed using real-time PCR. Results. The CC genotypes of rs7096206 and rs7095891 were significantly more frequent in the Nenets compared to Russians (p<0.001). In Dolgan-Nganasans, a trend towards a higher frequency of the CC genotype (p=0.020) of rs7095891 was observed. The case-control analysis in the Russian population revealed no statistically significant association of either polymorphism with bronchial asthma (p>0.05).

Conclusions. A higher frequency of MBL2 CC genotypes (rs7096206 and rs7095891), previously associated with reduced MBL levels, was identified in the Nenets population, with a similar trend in Dolgan-Nganasans. No association with BA was observed in Russians, highlighting the heterogeneity of genetic factors in this disease. These findings warrant further studies to evaluate the contribution of these genetic variants to respiratory morbidity in indigenous populations of the North.

1. Shen W., Zhang C., Wang C. et al. Association between polymorphisms in mannose-binding lectin 2 gene with pulmonary tuberculosis susceptibility. Hereditas. 2020;157:33.

2. Li X., Yang H., Zhang C. et al. MBL2 rs7095891 G > A polymorphism was associated with an increased risk of tuberculosis in the Chinese Uygur population. International Journal of Molecular Epidemiology and Genetics. 2018;9(5):64-70.

3. Kolosov V.P., Chuchalin A.G., Avdeev S.N. et al. Chronic respiratory diseases: epidemiological monitoring and prevention. Bulletin of Physiology and Pathology of Respiration. 2020;(76):8-18.

4. Queiroz M.A.F., Brito D.H.A., Lopes I.S. et al. Polymorphisms in the MBL2 gene are associated with the plasma levels of MBL and the cytokines IL-6 and TNF-α in severe COVID-19. Frontiers in Immunology. 2023;14:1151058.

5. Smolnikova M.V., Kasparov Ed.W., Malinchik M.A., Kopylova K.V. Genetic markers of children asthma: predisposition to disease course variants. Vavilovskii Zhurnal Genetiki i Selektsii=Vavilov Journal of Genetics and Breeding. 2023;27(4):393-400. DOI: 10.18699/VJGB-23-47