| 목적 : Normal-tension glaucoma (NTG) is a late-onset, and complex trait with multiple risk factors. In this study, we performed a genetic analysis of the mitochondrial gene and revealed the genetic risk variants in the NTG patients.방법 : DNA was extracted from peripheral blood of the NTG patients and normal control subjects. For the 20 NTG patients (discovery sample), the entire mitochondrial DNA (mtDNA) was sequenced using the next generation sequencing. From these results, we revealed new genetic risk variants for NTG patients. For the candidate genetic variants, we performed a disease-gene association study in the independent case-control populations (replication sample) (n=76 and n=82, respectively). For the replication sample, we used the Sanger’s sequencing method.결과 : This study identified 148 different novel mtDNA sequence changes. Of these, 21 sequence variants were identified at the frequency of more than 15%, which were located in the ND2-ND6, RNR1, RNR2, COX1, COX3, ATP6, ATP8, and CYTB genes. Of the 21 candidate genetic variants, the frequencies of 12372G>A (ND5 gene) and 14766C>T (CYTB gene) were significantly different between NTG patients and controls (18.9% vs. 2.4%, P=0.002; 8.0% vs. 0.0%, P=0.028). However, only the association with 12372G>A in ND5 gene resisted to Bonferroni correction for multiple tests.결론 : This study reveals a spectrum of mtDNA variants in patients with NTG. These results suggest that mitochondrial dysfunction may be a risk factor for the development of NTG. |