[Clinical analysis of dopa-responsive dystonia and mutation analysis of the GCH I gene].
OBJECTIVE
To investigate the clinical characteristics and GCH I gene mutations in patients with dopa-responsive dystonia (DRD).


METHODS
The clinical features of 3 families with 6 affected members and 8 sporadic cases were analyzed to determine the clinical characteristics, and 2 families with 4 affected members and 2 sporadic cases were screened for mutations of the GCH I gene.


RESULTS
Age at onset was (10 +/- 3) years. Onset occurred earlier in female (9 +/- 4) years than in male (12 +/- 1) years. The initial symptom was a gait disorder, dystonia or tremor in most patients and nine patients (64%) presented with diurnal fluctuation. Thirteen patients (93%) were cured and one was improved after administration of low doses of levodopa for 3 months and no long-term side effects of levodopa had occurred. Two independent mutations were found in three patients. Gln161Pro, a new missense mutation, was found in a sporadic case, leading to a relatively severe phenotype. The two patients with mild phenotype in one family were found to have Lys224Arg mutation, as previously described.


CONCLUSIONS
DRD patients have diverse phenotypes and diurnal fluctuation is an important feature. They have dramatic and sustained response to levodopa. There may be a correlation between genotype and phenotype. The detection of GCH I mutations is helpful in early diagnosis of non-typical cases.
Xie
Hui
H
Department of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China.
Wu
Zhi-ying
ZY
Wang
Ning
N
Li
Zhi-wen
ZW
Lin
Min-ting
MT
Murong
Shen-xing
SX
D017668:Age of Onset; D002648:Child; D002681:China; D004252:DNA Mutational Analysis; D015259:Dopamine Agents / Q000627:therapeutic use*; D004421:Dystonia / Q000175:diagnosis / Q000188:drug therapy / Q000235:genetics* / Q000503:physiopathology*; D042241:Early Diagnosis; D005260:Female; D006136:GTP Cyclohydrolase / Q000235:genetics*; D005838:Genotype; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use*; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D020125:Mutation, Missense; D010375:Pedigree; D010641:Phenotype; D016133:Polymerase Chain Reaction; D012737:Sex Factors; D016896:Treatment Outcome
D015259:Dopamine Agents; D007980:Levodopa; D006136:GTP Cyclohydrolase