Utility of MLPA in mutation analysis and carrier detection for Duchenne muscular dystrophy

Abstract

Context: Multiplex ligation probe amplification (MLPA) is a new technique to identify deletions and duplications and can evaluate all 79 exons in dystrophin gene in patients with Duchenne muscular dystrophy (DMD). Being semi-quantitative, MLPA is also effective in detecting duplications and carrier testing of females; both of which cannot be done using multiplex PCR. It has found applications in diagnostics of many genetic disorders.

Aim: To study the utility of MLPA in diagnosis and carrier detection for DMD.

Materials and methods: Mutation analysis and carrier detection was done by multiplex PCR and MLPA and the results were compared.

Results and conclusions: We present data showing utility of MLPA in identifying mutations in cases with DMD/BMD. In the present study using MLPA, we identified mutations in additional 5.6% cases of DMD in whom multiplex PCR was not able to detect intragenic deletions. In addition, MLPA also correctly confirmed carrier status of two obligate carriers and revealed carrier status in 6 of 8 mothers of sporadic cases.

Keywords: Duchenne and Becker muscular dystrophies; Dystrophin; carrier detection; multiplex ligation-dependent probe amplification.

Figure 1

(a) Normal MLPA peaks, (b) Heterozygous deletion in exons 8-10 in a carrier female, (c) Hemizygous deletion in exon 21, (d) Hemizygous duplication in exons 11-13