Mutation frequency analysis of mitochondrial ND1 gene associated with Leber hereditary optic neuropathy in Chinese population / 中华实验眼科杂志

ABSTRACT

Background Leber hereditary optic neuropathy (LHON)is a common inherited eye disease,which generally affects young adults with bilateral loss of central vision.Mutation frequency of Leber hereditary has not been fully clarified. Objective This study was to investigate the mutation frequency of mitochondrial NDI gene associated with LHON in Chinese population. Methods The proposal of the study was approved by Ethic Committee of Wenzhou Medical College.Written informed consent was obtained from each subject initial of this trial.Eight hundred and ninety-four LHON patients and 134 normal subjects were collected.Genomic DNA was extracted from peripheral blood leukocytes of the all participants.Polymerase chain reaction (PCR) was used to amplify and sequence analysis of the mitochondrial ND1 gene was performed and aligned with revised Cambridge Reference Sequence(rCRS) of mitochondrial DNA.Then mutated gene frequency was screened and analyzed. Results Mutational analysis of mitochondrial ND1 gene in 894 LHON patients revealed the presence of G3316A,T3394C,G3460A,C3497T,G3635A,G3733A,and T4216C.11.19％ LHON patients (100/894 ) were found to be associated with the gene mutations mentioned above,and 3.24％ patients (29/894) showed the co-occurrence of three primary mutations.Mutation frequencies in LHON patients were 2.57％,2.23％,1.45％,3.80％,0.67％,0.11％,0.34％,respectively,and G3316A,T3394C,C3497T and T4216C also were detected in 134 normal controls with the mutation frequencies of 4.48％,2.99％,4.48％ and 1.49％,respectively.Mutation frequency analysis showed an insignificant difference in the mutations of G3316A,T3394C,C3497T and T4216C between LHON patients and normal controls (x2 =0.926,P=0.336;x2 =0.052,P=0.820; x2 =0.142,P=0.707;P=0.129).G3376A,G3496T,G3700A,A4136G,T4160C and C4171A were absent in Chinese LHON patients. Conclusions Mitoehondrial ND1 gene in LHON is a mutational hotspot in Chinese population,11.19％ (100/894)associated with LHON was caused by ND1 gene mutation.G3635A,G3733A may be rare pathological mutation in Chinese population.However,G3316A,T3394C,C3497T and T4216C are insufficient to produce the clinical phenotype,but they may play a synergic role for penetrance and phenotypic manifestation in LHON.