Hexanucleotide Repeat Expansion in C9ORF72 Is Not Detected in the Treatment-Resistant Schizophrenia Patients of Chinese Han.

Xijia Xu,Xiaolan Wang,Xiaomeng Shi,Jie Lv,Jing Sun,Xiaowei Tang,Xiaobing Zhang,Mingzhong Wang,Hui Yao,Shiping Xie,Shuiping Lu,Jingping Zhao

doi:10.1371/journal.pone.0145347

Abstract

Hexanucleotide (GGGGCC) repeat expansion in C9ORF72 (HRE) causes frontotemporal lobar degeneration, frontotemporal dementia–amyotrophic lateral sclerosis, and amyotrophic lateral sclerosis. HRE was also seen in the genomes of patients suffering from several other degenerative diseases. However, whether it is present in the treatment-resistant schizophrenia patients remains unknown. Genotyping 386 patients suffering from treatment-resistant schizophrenia using the method of Repeat-Primed PCR, we reported here that no HRE was detected in the patients of Chinese Han.

Highlights

Hexanucleotide (GGGGCC) repeat occurs in the first intron of human C9ORF72 with different number of repeats usually fewer than 20
The hexanucleotide repeat expansion (HRE, greater than 30 repeats) causes FTLD, FTD−ALS, and ALS [1,2] likely due to toxicity of the transcribed repeat, toxicity of protein dipeptides translated from the transcribed repeat, or loss of function of C9ORF72 [1, 3,4,5]
It is present in 46.0% of familial ALS and 21.1% of sporadic ALS in the Finnish population [2], approximately 6% of sporadic and 25% of familial Caucasian FTLD cases [6], 27.1% of fALS and 3.2% of sALS in Spanish [7], only 0.3% of sALS [8] and no patients with fALS in Chinese [9], and 0.4% of sALS and no patients with fALS in Japanese [10]

Summary

Introduction

Hexanucleotide (GGGGCC) repeat occurs in the first intron of human C9ORF72 with different number of repeats usually fewer than 20. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. A research on a large population of patients with FTLD revealed that the presentation with late onset psychosis was significantly more frequent in HRE patients than in non-HRE ones [18] and 2 in 298 (0.67%) patients from Europe with schizophrenia or schizoaffective disorder were found to carry HRE [19].

Results

Conclusion