Screening of common mitochondrial mutations in Chinese patients with mitochondrial encephalomyopathies.
To investigate the spectrum of common mitochondrial mutations in Northern China during the years of 2000-2005, 552 patients of mitochondrial encephalomyopathies clinically diagnosed as MELAS, MERRF or Leigh's syndrome, 14 cases of LHON and 46 cases of aminoglycoside induced deafness along with their family members, accepted routine point mutation tests at nucleotide positions 3243, 8344, 8993, 11778 or 1555 in mitochondrial genome. PCR-RFLP analysis, site-specific PCR and PCR-sequencing methods were used to identify the mutations. Fifty-seven cases with A3243G mutation, 4 cases with A8344G, 2 cases with T8993C and 1 case with T8993G were identified from the 552 encephalomyopathy patients. In addition, one case with G11778A was found from the 14 cases of LHON, and 5 cases with A1555G from the 46 cases of aminoglycoside ototoxicity patients. Additional screening for T8356G and T3271C merely had limited significance for the diagnosis of MERRF and MELAS. Differential diagnosis among mitochondrial encephalomyopathies was often complicated due to many similar clinical manifestations. For A3243G mutation, the proportion of mutant mtDNA was not related to severity of the disease but to the age of onset.
Qi
Yu
Y
Central Laboratory, Peking University First Hospital, Beijing, PR China. qiyu0724@yahoo.com
Zhang
Ying
Y
Wang
Zhaoxia
Z
Yang
Yanling
Y
Yuan
Yun
Y
Niu
Shulan
S
Pei
Pei
P
Wang
Songtao
S
Ma
Yinan
Y
Bu
Dingfang
D
Zou
Liping
L
Fang
Fang
F
Xiao
Jing
J
Sun
Fang
F
Zhang
Yao
Y
Wu
Ye
Y
Wang
Shuang
S
Xiong
Hui
H
Wu
Xiru
X
D017668:Age of Onset; D000617:Aminoglycosides / Q000633:toxicity; D044466:Asian People / Q000235:genetics; D002681:China; D004272:DNA, Mitochondrial / Q000235:genetics*; D005820:Genetic Testing; D006311:Hearing Disorders / Q000139:chemically induced / Q000235:genetics; D006801:Humans; D007888:Leigh Disease / Q000235:genetics; D017241:MELAS Syndrome / Q000235:genetics; D017243:MERRF Syndrome / Q000235:genetics; D017237:Mitochondrial Encephalomyopathies / Q000235:genetics*; D029242:Optic Atrophy, Hereditary, Leber / Q000235:genetics; D017354:Point Mutation
D000617:Aminoglycosides; D004272:DNA, Mitochondrial