Clinical and laboratory survey of 65 Chinese patients with Leigh syndrome.
BACKGROUND
Leigh syndrome is an inherited neurodegenerative disease that emerges in infancy and childhood and presents with a clinically heterogeneous variety of neuromuscular and non-neuromuscular disorders. It can result from the inheritance of mutations in either nuclear or mitochondrial DNA. In the current study, we performed a retrospective study in 65 patients in order to investigate the clinical and genetic characteristics of Leigh syndrome in Chinese patients.


METHODS
Sixty-five unrelated cases (35 men and 30 women) who were hospitalized in the past 12 years were reviewed. Diagnosis was based on both the clinical presentation and the characteristic neuropathologic findings of bilateral symmetric necrotizing lesions in the basal ganglia and brain stem as detected using cranial computed tomography (CT) scan or magnetic resonance imaging (MRI). The differential diagnosis of organic acidurias and fatty acid beta-oxidation defects were performed. Specific point mutations and deletions in mitochondrial DNA (T8993G, T8993C, T9176C, A8344G, A3243G) were screened by PCR-restriction analysis and Southern blot. The SURF1 gene was sequenced. Skeletal muscle biopsies were performed in 17 (26.2%) of the patients. The diagnosis was confirmed by autopsy in 6 (9.2%) patients.


RESULTS
The patients had various forms of metabolic encephalomyopathy. Fifty-nine (90.8%) of the patients had the typical neuroradiological features of Leigh syndrome, including symmetrical necrotizing lesions scattered within the basal ganglia, thalamus and brain stem. Twenty (30.8%) patients were confirmed by genetic, biochemical analysis and autopsy. Specific point mutations in mitochondrial DNA were found in 5 cases (7.7%). Of these, the A8344G mutation was detected in 2 patients. The T8993G, T8993C, and A3243G point mutations were identified in 3 other patients, respectively. SURF1 mutations associated with cytochrome c oxidase deficiency were identified in 8 (12.3%) families by DNA sequencing. A G604C mutation was identified in 6 (9.2%) patients. The genotypes of 52 patients remained unknown.


CONCLUSIONS
Leigh syndrome presents as a diverse array of clinical features and can result from specific mutations in nuclear or mitochondrial DNA. In this study, SURF1 mutations associated with cytochrome c oxidase deficiency were identified in 8 (12.3%) out of 65 patients with Leigh syndrome. It indicates that SURF1 mutations might be a common cause of Leigh syndrome in China. The etiology of Leigh syndrome in Chinese patients represents a persistent challenge to clinicians.
Yang
Yan-ling
YL
Department of Pediatrics, Peking University First Hospital, Beijing 100034, China. organic.acid@126.com
Sun
Fang
F
Zhang
Yao
Y
Qian
Ning
N
Yuan
Yun
Y
Wang
Zhao-xia
ZX
Qi
Yu
Y
Xiao
Jiang-xi
JX
Wang
Xiao-ying
XY
Qi
Zhao-yue
ZY
Zhang
Yue-hua
YH
Jiang
Yu-wu
YW
Bao
Xin-hua
XH
Qin
Jiong
J
Wu
Xi-ru
XR
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D030401:Cytochrome-c Oxidase Deficiency / Q000235:genetics; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007888:Leigh Disease / Q000235:genetics* / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D008297:Male; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D009154:Mutation; D011506:Proteins / Q000235:genetics; D012189:Retrospective Studies; D016896:Treatment Outcome
D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D011506:Proteins; C092928:Surf-1 protein