Dystrophin gene analysis in iranian duchenne and becker muscular dystrophy patients; discovery of 18 novel mutations

Mohammadkazem Bakhshandeh,1,* Ali ahani,2 Atiyeh majidi,3

1. Assistant Professor, Farhikhtegan Hospital, Islamic Azad Tehran Medical University
2. Mendel medical genetic laboratory, Tehran, Iran
3. Doctor Of Medicine, Tehran University of Medical Sciences(TUMS), Tehran, Iran.

Abstract


Introduction

Dystrophinopathy including duchenne muscular dystrophy (dmd) and becker muscular dystrophy (bmd), is the most prevalent type of muscular dystrophy. we evaluate the phenotype and genotypic features of patients suffering from dystrophinopathy in our country.

Methods

From january 2015 to april 2018, all male patients, and one female, which are suspected to becker/duchenne muscular dystrophy were enrolled in this study. subjects had referred for genetic analysis by multiplex ligation-dependent probe amplification(mlpa) method followed by next generation targeted sequencing.

Results

Totally, 155 suspected patients have been evaluated. the age range of the cases were from 23 months to 45.5 years. mlpa diagnosed 109 subjects, 56% deletion and 5.16% deletion. in 62% of cases, dmd gene deletion clustered in the distal hotspot and only 12% showed deletions in the proximal hotspot. overall, 30 patients (27%) had single exon deletion or duplication; exon 50 was the most involved region (9.12%) . based on clinical phenotype there was no significant difference between patients with single / multiple exon deletion/duplication (p>0.05). findings of the current study are in consistent with other reported cases in other ethnic populations. also, next generation sequencing was performed for 35 subjects and 18 novel mutations along with 17 previously known pathogenic variants were detected.

Conclusion

There was no significant correlation between severity of disease and location of the mutations. (p>0.05)findings of the current study are in consistent with other reported cases in other ethnic populations.

Keywords

Duchenne muscular dystrophy (dmd), becker muscular dystrophy (bmd), multiplex ligation-dependent pro