Whole genome sequencing reveals a 7 base-pair deletion in DMD exon 42 in a dog with muscular dystrophy

• Published in: Mammalian genome Vol. 28; no. 3-4; pp. 106 - 113
• Main Authors: Nghiem, Peter P., Bello, Luca, Balog-Alvarez, Cindy, López, Sara Mata, Bettis, Amanda, Barnett, Heather, Hernandez, Briana, Schatzberg, Scott J., Piercy, Richard J., Kornegay, Joe N.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.04.2017; Springer Nature B.V
• Subjects: Alternative Splicing - genetics; Animal Genetics and Genomics; Animals; Biomedical and Life Sciences; Cell Biology; Disease Models, Animal; Dogs; Dystrophin - genetics; Exons - genetics; Human Genetics; Humans; Introns - genetics; Life Sciences; Mice; Mice, Inbred mdx - genetics; Muscular Dystrophies - genetics; Mutation; RNA, Messenger; Sequence Deletion - genetics; Whole Genome Sequencing - methods; Sanger Sequencing; Duchenne Muscular Dystrophy; Duchenne Muscular Dystrophy Patient; Conventional Polymerase Chain Reaction
• ISSN: 0938-8990; 1432-1777
• DOI: 10.1007/s00335-016-9675-2

Dystrophin is a key cytoskeletal protein coded by the Duchenne muscular dystrophy ( DMD ) gene located on the X-chromosome. Truncating mutations in the DMD gene cause loss of dystrophin and the classical DMD clinical syndrome. Spontaneous DMD gene mutations and associated phenotypes occur in several other species. The mdx mouse model and the golden retriever muscular dystrophy (GRMD) canine model have been used extensively to study DMD disease pathogenesis and show efficacy and side effects of putative treatments. Certain DMD gene mutations in high-risk, the so-called hot spot areas can be particularly helpful in modeling molecular therapies. Identification of specific mutations has been greatly enhanced by new genomic methods. Whole genome, next generation sequencing (WGS) has been recently used to define DMD patient mutations, but has not been used in dystrophic dogs. A dystrophin-deficient Cavalier King Charles Spaniel (CKCS) dog was evaluated at the functional, histopathological, biochemical, and molecular level. The affected dog’s phenotype was compared to the previously reported canine dystrophinopathies. WGS was then used to detect a 7 base pair deletion in DMD exon 42 (c.6051-6057delTCTCAAT mRNA), predicting a frameshift in gene transcription and truncation of dystrophin protein translation. The deletion was confirmed with conventional PCR and Sanger sequencing. This mutation is in a secondary DMD gene hotspot area distinct from the one identified earlier at the 5′ donor splice site of intron 50 in the CKCS breed.