Aim. Congenital heart defect formation, including atrioventricular comunication is frequently associated with mutations in gene COL3A1, wich codes procollagen of III type. Collagen synthesis impairment lies in the basis of many disease connected with the syndrome of connective tissue dysplasia. Characteristic appearances are damaged ligaments, tendons, muscular system and valvular heart defects.
The purpose is to determine the distribution of the genotypes regarding polymorphic locus 2209G>A (AluI) gene COL3A1 in children with atrioventricular canal defect, control group and comparison group (children with chromosomal pathology, trisomy 21 without AVCD).
Methods. The extraction and clearance of DNA from leucocytes from peripheral blood was performed by the method of salting out. In order to identify polymorphic locus 2209G>A (AluI) gene collagen ІІІ type COL3A1. The method of RFLP of the PCR products was used.
Results. It is constituted that the distribution of the genotypes by the polymorphic variant 2209G>A (AluI) gene COL3A1 in the examined and control group and confirmed its responsibility in Hardy-Weinberg principle. The differences in the frequencies of the examined group in children with AVCD in comparison with control group did not reach significant values (р>0.05). No allele and genotype of polymorphic locus COL3A1 2209G>A gene there are no associations with formation of the AVCD in children. Presence of the genotype 2209GG of COL3A1 gene is associated with the larger ventricular defect. Most valuable differences in the frequencies of the genotypes are determined between groups A and B according to the Rastelli classification in comparison with the control group.
Conclusions. Presence of the genotypes GА/АA of the polymorphic locus 2209G>A correlates with the size of the ventricular septal defect. Prognostic marker which contributes to three times increases the risk of the development of the type B AVCD is the presence of the allele G of the 2209G>A locus of COL3A1 gene.