A familial study in serum dopamine-β-hydroxylase levels in torsion dystonia

Dopamine-β-hydroxylase activity and immunoreactive dopamine-β- hydroxylase levels were measured in the serum of patients with the autosomal recessive and autosomal dominant forms of torsion dystonia, as well as in unaffected members of their families. The enzyme levels do not differentiate between the two forms of the disease. The elevated serum dopamine-β-hydroxylase levels in some patients with torsion dystonia reflect genetic influences rather than clinical symptomatology. Patients with torsion dystonia could not be classified with the autosomal dominant form or autosomal recessive form according to the serum dopamine-β- hydroxylase levels.