Abstract | PURPOSE: The diagnostic rate for Mendelian diseases by exome sequencing (ES) is typically 20-40%. The low rate is partly because ES misses deep-intronic or synonymous variants leading to aberrant splicing. In this study, we aimed to apply RNA sequencing ( RNA-seq) to efficiently detect the aberrant splicings and their related variants. METHODS: Aberrant splicing in biopsied muscles from six nemaline myopathy (NM) cases unresolved by ES were analyzed with RNA-seq. Variants related to detected aberrant splicing events were analyzed with Sanger sequencing. Detected variants were screened in NM patients unresolved by ES. RESULTS: We identified a novel deep-intronic NEB pathogenic variant, c.1569+339A>G in one case, and another novel synonymous NEB pathogenic variant, c.24684G>C (p.Ser8228Ser) in three cases. The c.24684G>C variant was observed to be the most frequent among all NEB pathogenic variants in normal Japanese populations with a frequency of 1 in 178 (20 alleles in 3552 individuals), but was previously unrecognized. Expanded screening of the variant identified it in a further four previously unsolved nemaline myopathy cases. CONCLUSION: These results indicated that RNA-seq may be able to solve a large proportion of previously undiagnosed muscle diseases.
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Authors | Kohei Hamanaka, Satoko Miyatake, Eriko Koshimizu, Yoshinori Tsurusaki, Satomi Mitsuhashi, Kazuhiro Iwama, Ahmed N Alkanaq, Atsushi Fujita, Eri Imagawa, Yuri Uchiyama, Nozomu Tawara, Yukio Ando, Yohei Misumi, Mariko Okubo, Mitsuko Nakashima, Takeshi Mizuguchi, Atsushi Takata, Noriko Miyake, Hirotomo Saitsu, Aritoshi Iida, Ichizo Nishino, Naomichi Matsumoto |
Journal | Genetics in medicine : official journal of the American College of Medical Genetics
(Genet Med)
Vol. 21
Issue 7
Pg. 1629-1638
(07 2019)
ISSN: 1530-0366 [Electronic] United States |
PMID | 30467404
(Publication Type: Evaluation Study, Journal Article)
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Chemical References |
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Topics |
- Humans
- Japan
- Muscle Proteins
(genetics)
- Muscle, Skeletal
(metabolism)
- Mutation
- Myopathies, Nemaline
(genetics)
- RNA Splicing
- Sequence Analysis, RNA
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