Clinical features and gene analysis in Korean patients with early-onset Parkinson disease.
BACKGROUND
Systematic analysis of clinical features and gene mutations has not been performed in Korean patients with early-onset Parkinson disease (PD).


OBJECTIVE
To investigate the clinical characteristics and genetic background of Korean patients with early-onset PD.


METHODS
Clinical and genetic study.


METHODS
University hospital.


METHODS
Ninety-four patients with early-onset PD (mean +/- SD age at onset, 39.8 +/- 7.3 years) of 1100 patients with PD.


METHODS
Analysis of clinical characteristics and mutation analysis of the parkin and PTEN-induced kinase (PINK1) genes by direct sequencing and gene-dosage analysis using the multiplex ligation-dependent probe amplification technique.


METHODS
The correlation between age at onset and clinical characteristics and the clinical features of patients with onset before age 30 years vs patients with onset after age 30 years.


RESULTS
Because age at onset was younger, levodopa-induced dyskinesia and off-dystonia were more frequently observed (P=.008). Patients affected before age 30 years showed more frequent levodopa-induced dyskinesia and off-dystonia (P=.002). We identified 3 patients (5%) with parkin gene mutations but none with the PINK1 mutation.


CONCLUSIONS
Earlier onset of levodopa-induced dyskinesia and off-dystonia were characteristic features of early-onset PD, especially before an onset age of 30 years. However, parkin gene mutations were less frequent in these patients than in Japanese groups reported elsewhere.
Chung
Eun Joo
EJ
Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-Dong, Kangnam-Gu, Seoul 135-710, Korea.
Ki
Chang-Seok
CS
Lee
Won Yong
WY
Kim
In-Suk
IS
Kim
Ji-Youn
JY
D000328:Adult; D017668:Age of Onset; D004409:Dyskinesia, Drug-Induced / Q000453:epidemiology / Q000235:genetics; D005260:Female; D006801:Humans; D007723:Korea / Q000453:epidemiology; D007980:Levodopa / Q000009:adverse effects / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010300:Parkinson Disease / Q000188:drug therapy / Q000453:epidemiology* / Q000235:genetics*; D011494:Protein Kinases / Q000235:genetics; D044767:Ubiquitin-Protein Ligases / Q000235:genetics; D000099202:PTEN-Induced Putative Kinase
D007980:Levodopa; D011494:Protein Kinases; D044767:Ubiquitin-Protein Ligases; D000099202:PTEN-Induced Putative Kinase; C111567:parkin protein