Biallelic GGGCC repeat expansion leading to NAXE-related mitochondrial encephalopathy.

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

SUBMITTER: Ozaki K 

PROVIDER: S-EPMC11512015 | biostudies-literature | 2024 Oct

REPOSITORIES: biostudies-literature