Microarray-based mutation detection in the dystrophin gene

• Type of Material: Article
• Authors: Madhuri Hegde, Emory University; Ephrem L.H. Chin, Emory University; Jennifer Mulle, Emory University; David T. Okou, Emory University; Stephen Warren, Emory University; Michael Zwick, Emory University
• Language: English
• Date: 2008-09
• Publisher: Wiley: 12 months
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2008 Wiley-Liss, Inc.
• Final Published Version (URL): http://onlinelibrary.wiley.com/doi/10.1002/humu.20831/abstract
• Title of Journal or Parent Work: Human Mutation
• ISSN: 1059-7794
• Volume: 29
• Issue: 9
• Start Page: 1091
• End Page: 1099
• Grant/Funding Information: This work was supported, in part, by NIH grants MH805832 to JGM and MH076439 to MEZ.
• Keywords: DMD; CNV; microarray; Duchenne Muscular Dystrophy; exonic-copy number variation; dystrophin; Becker Muscular Dystrophy; CGH array; BMD
• Research Categories: Biology, Genetics

Abstract

Duchenne and Becker muscular dystrophies (DMD and BMD) are X-linked recessive neuromuscular disorders caused by mutations in the dystrophin gene affecting approximately 1 in 3,500 males. The human dystrophin gene spans > 2,200 kb, or roughly 0.1% of the genome, and is composed of 79 exons. The mutational spectrum of disease-causing alleles, including exonic copy number variations (CNVs), is complex. Deletions account for approximately 65% of DMD mutations and 85% of BMD mutations. Duplications occur in approximately 6–10% of males with either DMD or BMD. The remaining 30–35% of mutations consist of small deletions, insertions, point mutations, or splicing mutations, most of which introduce a premature stop codon. Laboratory analysis of dystrophin can be used to confirm a clinical diagnosis of DMD, characterize the type of dystrophin mutation, and perform prenatal testing and carrier testing for females. Current dystrophin diagnostic assays involve a variety of methodologies, including multiplex PCR, Southern blot analysis, MLPA, DOVAM-S, and SCAIP; however, these methods are time-consuming, laborious, and do not accurately detect duplication mutations in the dystrophin gene. Furthermore, carrier testing in females is often difficult when a related affected male is unavailable. Here we describe the development, design, validation, and implementation of a high-resolution CGH microarray-based approach capable of accurately detecting both deletions and duplications in the dystrophin gene. This assay can be readily adopted by clinical molecular testing laboratories and represents a rapid, cost-effective approach for screening a large gene, such as dystrophin.