Speakers - 2026

Title: Aspects of molecular genetic polymorphism of the dystrophin gene in Uzbekistan

Abstract

Introduction: At present, extensive data have been accumulated on deletion spectra in the dystrophin gene in various populations worldwide, and certain population differences have been established.

Aim of the study: To investigate the genetic polymorphism of the dystrophin gene among patients with Duchenne  muscular dystrophy and to determine the frequency of dystrophin gene mutation carriage among female relatives in families affected by DMD  in the population of Uzbekistan.

Materials and methods: Molecular genetic studies were conducted  MLPA diagnostics to detect deletions and duplications in patients with DMD. MLPA diagnostics was performed in 91 patients with DMD from 81 families, including 84 patients (92.3%) with Duchenne muscular dystrophy and 7 patients (8.6%) with Becker muscular dystrophy. The analysis covered all 79 exons of the dystrophin gene.

Results and discussion: According to the results of molecular diagnostics, deletions were not detected in 33 patients (36.3%) from 32 families (39.5%), while deletions of the dystrophin gene of varying length—from one to nine exons—were identified in 58 patients (63.7%) from 49 families (60.5%). Extended deletions were verified in 65.3% of families, whereas single-exon deletions were observed in 34.7% of families.

The main deletion spectrum was located in the distal part of the dystrophin gene at the 3′ end (deletions of exons 40–60), accounting for 81.6% (40 families, 47 patients). Proximal deletions of the dystrophin gene at the 5′ end (deletions of exons 3–19) were more common in familial forms of DMD/BMD, while in sporadic cases, deletions in the distal part of the dystrophin gene at the 3′ end (deletions of exons 40–60) were more frequently identified. Among distal mutations, deletions of the following exons were most common: exon 50 in 24 cases, exon 51 in 24 cases, exon 52 in 21 cases, exon 48 in 16 cases, and exon 53 in 14 cases. No deletions were detected in the promoter region or in exons 32, 42, and 60. Among proximal mutations, deletions of exon 19 (8 cases) and exon 17 (6 cases) were most frequently observed.

Conclusions: According to MLPA diagnostics in patients with Duchenne muscular dystrophy, mutations were identified in 16 of the 79 analyzed exons, which provides a basis for using the DMD-del1 and DMD-del2 kits for the diagnosis of “major” deletions in the dystrophin gene in the population of Uzbekistan.