Year: 2024
Type: article
Abstract: Repeat expansions cause at least 50 hereditary disorders, including Friedreich ataxia and other diseases known to cause mitochondrial dysfunction. We identified a patient with NAXE-related mitochondrial encephalopathy and novel biallelic GGGCC repeat expansion as long as ~200 repeats in the NAXE promoter region using long-read sequencing. In addition to a marked reduction in the RNA and protein, we found a marked reduction in nascent RNA in the promoter using native elongating transcript-cap analysis of gene expression (NET-CAGE), suggesting transcriptional suppression. Accordingly, CpG hypermethylation was observed in the repeat region. Genetic analyses determined that homozygosity in the patient was due to maternal chromosome 1 uniparental disomy (UPD). We assessed short variants within NAXE including the repeat region in the undiagnosed mitochondrial encephalopathy cohort of 242 patients. This study identified the GGGCC repeat expansion causing a mitochondrial disease and suggests that UPD could significantly contribute to homozygosity for rare repeat-expanded alleles.
Source: npj Genomic Medicine
Authors: Kokoro Ozaki, Yukiko Yatsuka, Yoshinobu Oyazato, Atsushi Nishiyama, Kazuhiro R. Nitta, Yoshihito Kishita, Takuya Fushimi, Masaru Shimura, Shohei Noma, Yohei Sugiyama, Michihira Tagami, Moe Fukunaga, Hiroko Kinoshita, Tomoko Hirata, Wataru Suda, Yasuhiro Murakawa, Piero Carninci, Akira Ohtake, Kei Murayama, Yasushi Okazaki
Language: English
Subfield: Cellular and Molecular Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $3,890
Awards: Establishment of an intronic variant evaluation system aimed at improving the diagnosis rate of mitochondrial disease., G2521393710, G2693237995, Establishment of multi-layered omics analysis for mitochondrial disease patients, Identification of mitochondrial disease-causing genes focusing on retrotransposons, G4513581909, G4656619442, Mitochondrial disease gene analysis focusing on RNA splicing abnormalities, G5758112025, G6039459496, G6565027075, 長鎖・短鎖シークエンシング技術の統合による構造変異の検出と非翻訳領域情報を駆使した未診断症例の解決
OpenAlex ID: W4403770604