[Analysis of clinical phenotype and CGH1 gene mutations in a family affected with dopa-responsive dystonia].

OBJECTIVE

To explore genetic mutations and clinical features of a pedigree affected with dopa-responsive dystonia.

METHODS

PCR and Sanger sequencing were applied to detect mutations of the GCH1 gene among 7 members from the pedigree.

RESULTS

The family was detected to have a known heterozygous mutation of the GCH1 gene (c.550C>T). For the 7 members from the pedigree, the age of onset has ranged from 13 to 60 years. The mother of the proband has carried the same mutation but was still healthy at 80. The symptoms of the other three patients were in slow progression, with diurnal fluctuation which can be improved with sleeping, dystonias of lower limbs, and tremor of both hands. Treatment with small dose of levodopa has resulted in significant improvement of clinical symptoms. By database analysis, the c.550C>T mutation was predicted as probably pathological.

CONCLUSION

The c.550C>T mutation probably underlies the disease in this pedigree. The clinical phenotypes of family members may be variable for their ages of onset. Some may even be symptom free.