Objective: Autosomal dominant progressive external ophthalmoplegia (adPEO) is a genetically heterogeneous, adult-onset disease. Thus far, disease loci have been identified on four different nuclear genes. The purpose of this study is to identify the gene responsible for causing adPEO in a Chinese family.

Methods: Clinical data and genomic DNA of a Chinese adPEO family were collected following informed consent. Gene scan by two-point linkage analysis was performed for four genes, and mutation screening was conducted in the Twinkle (PEO1) gene by direct sequencing.

Results: A maximum two-point LOD score of 2.8 at theta=0.00 was obtained with marker D10S192 in close proximity to PEO1. A novel missense mutation (c.1423G>A, p.475A>T) was identified.

Conclusions: This study widens the mutation spectrum of PEO1 and is the first to report the PEO1 mutation in the Chinese population.