[Pubmed] A Novel Truncating Pathogenic Variant in RRM2B in a Kurdish Family With Autosomal-Dominant Chronic Progressive

[RSS-Bot]

J Clin Neuromuscul Dis. 2026 Mar 1;27(3):108-111. doi: 10.1097/CND.0000000000000514. Epub 2026 Mar 3.

ABSTRACT

OBJECTIVES: To report a family with autosomal-dominant chronic progressive external ophthalmoplegia due to a novel truncating pathogenic variant in RRM2B and to show the challenges facing clinicians in diagnosing rare neuromuscular diseases.

METHODS: Four family members were examined. Muscle biopsy, mitochondrial DNA analysis, next generation sequencing, and targeted mitochondrial gene panel followed by Sanger sequencing and complementary deoxyribonucleic acid analysis were performed.

RESULTS: A novel heterozygous RRM2B truncating variant c.968_972del p.(Phe323*) was identified. complementary deoxyribonucleic acid analysis showed expression of both RRM2B alleles.

CONCLUSIONS: The proband was initially misdiagnosed as myasthenia gravis. Based on the phenotype and family history, chronic progressive external ophthalmoplegia was suspected and confirmed by finding of a novel RRM2B variant. The detection of another truncating pathogenic variant in exon 9 of RRM2B further supports this exon as mutation hot spot and underlines the role of the C-terminal highly conserved amino acids for the interaction of the p53R2 dimer with the R1 dimer.

PMID:41766080 | DOI:10.1097/CND.0000000000000514


Source: https://pubmed.ncbi.nlm.nih.gov/4176608 ... t6+133c1fe