Frequency of GCH1 deletions in Dopa-responsive dystonia.
We performed a systematic study on the frequency of point mutations and deletions of the gene GCH1 in dopa-responsive dystonia (DRD). A total of 136 dystonia patients were studied. Fifty of these had a sustained response to oral L-Dopa therapy (group 1: definite diagnosis of DRD), whereas the response to L-Dopa was incomplete or not tested in 86 patients (group 2: possible diagnosis of DRD). We found a GCH1 point mutation in 27 patients of group 1 (54%) and in four patients of group 2 (5%). Of these, nine single and one double mutation have not been described before. GCH1 deletions were detected in four patients of group 1 (8%) and in one patient of group 2 (1%). Among GCH1 point-mutation-negative patients with a definite diagnosis of DRD (group 1), the frequency of GCH1 deletions was 17% (4/23). We conclude that GCH1 deletion analysis should be incorporated into the routine molecular diagnosis of all patients with DRD with a sustained response to L-Dopa.
Zirn
B
B
Institut für Humangenetik, University of Giessen, Schlangenzahl 14, D-35392 Giessen, Germany.
Steinberger
D
D
Troidl
C
C
Brockmann
K
K
von der Hagen
M
M
Feiner
C
C
Henke
L
L
Müller
U
U
D000293:Adolescent; D000328:Adult; D000978:Antiparkinson Agents / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D002869:Chromosome Aberrations; D002872:Chromosome Deletion; D015331:Cohort Studies; D004252:DNA Mutational Analysis; D020821:Dystonic Disorders / Q000175:diagnosis / Q000188:drug therapy / Q000235:genetics*; D005260:Female; D006136:GTP Cyclohydrolase / Q000235:genetics*; D005787:Gene Frequency; D005799:Genes, Dominant; D006801:Humans; D007223:Infant; D007980:Levodopa / Q000627:therapeutic use*; D008297:Male; D018895:Microsatellite Repeats; D019683:Penetrance; D017354:Point Mutation; D020539:Sequence Analysis, Protein
D000978:Antiparkinson Agents; D007980:Levodopa; D006136:GTP Cyclohydrolase