第十一届北京罕见病学术大会暨2023京津冀罕见病学术大会征文(035)

1北京大学第一医院神经内科

神经系统小血管病探索北京市重点实验室

2北京大学第一医院老年病内科

3北京积水潭医院神经内科

赵杨¹，侯越²，赵旭彤^{1， 3}，刘付童玲¹，

俞萌¹，张巍¹，谢志颖¹，袁云¹，王朝霞¹

Background: Progressive external ophthalmoplegia (PEO) is a common subtype of mitochondrial encephalomyopathy.

Objective: The study aimed to investigate the correlation between mitochondrial DNA (mtDNA) abnormalities and clinical manifestations in Chinese patients with single large-scale mtDNA deletion presenting with PEO.

Methods: This is a retrospective single-center study. Patients with PEO who had a single large deletion in mitochondrial DNA were included in this study. The associations between mtDNA deletion patterns and clinical characteristics were analyzed.

Results: In total， 155 patients with mitochondrial PEO carrying single large scale mtDNA mutations were enrolled， including 137 chronic progressive external ophthalmoplegia (CPEO) and18 Kearns-Sayre syndrome (KSS) patients. The mtDNA deletions ranged from 2225 bp to 9131 bp， with the most common deletion being 4977 bp in length (8470-8482:13447-13459). The KSS group had longer deletions than the CPEO group (P = 0.004)， and a higher number of deleted enzyme complex encoding genes (P = 0.001) and tRNA genes (P = 0.009) were observed， correspondingly. A weak negative correlation between mtDNA deletion length and age of onset (P < 0.001， r = -0.369) was observed. However， we did not find any significant correlation between mtDNA deletions and the number of ragged red fibers (RRF)， ragged blue fibers (RBF)， or COX-negative fibers on muscle pathological changes.

Conclusion: We reported a large Chinese cohort consisting of mitochondrial PEO patients with single large-scale mtDNA deletions. Our results demonstrated that the length and location of mtDNA deletions may influence the age of onset and phenotype of patients， but not the extent of muscle pathology.

Keywords: Mitochondrial DNA; single large-scale deletion; chronic progressive external ophthalmoplegia; Kearns-Sayre syndrome; muscle biopsy