The importance of genetic factors in the development of celiac disease in children of the Uzbek population
Authors:   Center for the Development of Professional Qualifications of Medical Workers of the Republic of Uzbekistan, Tashkent, Abdujabarova Z.M. , Kamilova A.T. ,   Republican Specialized Scientific and Practical Center of Pediatrics Republic of Uzbekistan, Tashkent
Published: January 2021

The results of genetic studies have proven the relationship of celiac disease with class II genes of the major histocompatibility complex (HLA), in particular with the DQ locus. The presence of specific alleles at the HLA-DQ locus is necessary, but insufficient, for the realization of the disease phenotype. In Uzbekistan, the distribution of HLA markers in children with celiac disease has not been studied and these studies are required. Purpose — to establish the peculiarities of the distribution of HLA II class celiac disease alleles in children in the Uzbek population. Materials and methods. We examined 54 children with celiac disease of the Uzbek population, who were registered and receiving inpatient treatment at the Republican Specialized Scientific and Practical Medical Center of Pediatrics. The age of the examined children was from 1 to 14 years old, the average age was 7.3±1.9 years. The control group consisted of 109 unrelated Uzbeks without immune diseases. Molecular typing of HLA II class genes was determined by DNA chain reaction polymerase. Results. As a result of gene typing, 48 (88.8%) out of 54 investigated had DQ2 and DQ8 haplotypes associated with celiac disease. Haplotypes with only DQ2 and DQ8 were found in 19 (39.5%) and 7 (14.5%), respectively. DQ2 from 48 children was found in 18 (37.5%) children in the trans-position, in 2 (4,1%) — as two copies of DQ2 dimers, and in 1 (2%) case in combination with DQ8. Only in one case (2%) was DQ8 found as two copies of DQ8 dimers. The frequency of occurrence of the HLA-DRB1*07 and *13 alleles was significantly higher than in the control group. The maximum value of the relative risk and the criterion of reliability are noted in the DQA1*0501 allele, i.e. it is positively associated with celiac disease (χ2=7.28, RR=2.03). Significance criterion and relative risk were observed in sick children with DQB1*0201 (χ2=6.74, RR=1.97) associated with celiac disease. The number of haplotype (DQA1*0501-DQB1*0201) was 36 (75%). Conclusions. A specific predisposition to celiac disease in children of the Uzbek population is associated with the genes HLA-DQA1*0501, HLA-DQB1*0201, HLA-DRB1*07 and *13. Alleles such as DRB1*15, DQA1*0102, DQB1*0303 and *0502, have a protective effect in the development of celiac disease in children of the Uzbek population. A high frequency of carriage of the DRB1*13 — HLA-DQА1*0501 and DQB1*0201 (DQ2 type) haplotype in Uzbeks (75%) was found, which requires a more thorough population genetic study of the Uzbek population for the HLA II class DRB1-DQA1-DQB1 genes. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of these Institutes. The informed consent of the patient was obtained for conducting the studies. No conflict of interest was declared by the authors. Key words: celiac disease, children, genetics, HLA class II.