Genetic Analysis of Forty MLPA-Negative Duchenne Muscular Dystrophy Patients by Whole-Exome Sequencing

J Mol Neurosci. 2022 May;72(5):1098-1107. doi: 10.1007/s12031-022-01980-5. Epub 2022 Feb 26.

Abstract

This manuscript aimed to determine the underlying point mutations causing Duchenne muscular dystrophy (DMD) in a heterogeneous group of Iranian patients, who are clinically suspected. Whole-exome sequencing was utilized to detect disease-causing variants in 40 MLPA-negative DMD patients. Disease-causing variants were detected in the DMD gene in 36/40 of the patients (90%), and 4/40 of them (10%) remained undiagnosed. WES analysis revealed that nonsense variant was the most common type in our study (23/36 of the cases). Besides, 12/36 of the cases had frameshift variant, and one of the patients had a likely pathogenic splice variant in the DMD gene. Carrier testing revealed that 21/40 of the mothers had the identified variant. Therefore, most variants were inherited (58.3%), while 19/40 were de novo (41. 7%). The present study has demonstrated the importance of performing WES to detect disease-causing point mutations in MLPA-negative DMD patients and to identify carrier females. Due to regulatory challenges, the clinical development of therapeutic approaches is time-consuming and may not be available to all patients shortly. Therefore, it appears that the techniques used to accurately detect disease-causing variants in carrier mothers are a more efficient solution to prevent the increased prevalence of DMD.

Keywords: Duchenne muscular dystrophy; Dystrophin; Multiplex ligation-dependent probe amplification; Whole-exome sequencing.

MeSH terms

  • Exome Sequencing
  • Female
  • Genetic Testing
  • Humans
  • Iran
  • Muscular Dystrophy, Duchenne* / genetics
  • Mutation