METHOD OF DIFFERENTIAL AND CONFIRMING MOLECULAR-GENETIC DIAGNOSIS OF CONGENITAL ANIRIDIA AND WAGR-SYNDROME

摘要

FIELD: biotechnology.;SUBSTANCE: method of differential and confirming the molecular genetic diagnosis of congenital aniridia and WAGR syndrome is described. The method provides that in a patient having clinical signs of aniridia, a sample of biological material is taken for the DNA diagnosis. Initially, large deletions with a size of at least one thousand base pairs of 11p13 region by the MLPA method are searched for. Based on the results of this search, further activities selected from the next set of diagnostic tools are produced. If a large deletion of the Hp 13 region, the locus of the WT1 and PAX6 genes, is detected and the deletions on the patient's genetic material are confirmed by fluorescent in situ hybridization (FISH) with a probe specific for the WT1 gene, the patient is exposed to a presumptive diagnosis of WAGR syndrome. In case of detection of large deletions of the 11p13 region that do not capture the locus of the WT1 gene and the locus of the PAX6 gene or its distant regulatory regions, and confirm deletions on the genetic material of the patient by the method of analysis of loss of heterozygosity by microsatellite markers, the patient is diagnosed with a congenital aniridia. In the absence of major deletions of the 11p13 region, sequencing of exons and flanking regions of the intron of the PAX6 gene is performed to find small intragenic mutations of this gene. Exons are sequenced from at least one of the groups: exon group 5, 6, 7, 8, 9 and/or exon group 1, 2, 3, 4, 10, 11, 12, 13. If a small intragenic mutation is detected as a result of sequencing, the pathogenicity of the detected genetic lesions in the PAX6 gene is checked in accordance with the ACMG (American College of Molecular Genetics) criteria. With evidence of the pathogenicity of the mutation, the patient is confirmed with a clinical diagnosis of congenital aniridia. Preferably, the genetic status of this change in the parents is determined to confirm the pathogenicity and clinical significance of the deletions or other mutations identified.;EFFECT: invention provides an effective confirmatory protocol and differential diagnosis of congenital aniridia and WAGR syndrome, taking into account the pronounced clinical polymorphism and molecular heterogeneity.;7 cl, 1 dwg