[Recessive dopa-responsive form of dystonia due to a mutation of the tyrosine hydroxylase gene].

The cause of Dystonia Musculorum Deformans (DMD) is most frequently unknown, therefore the treatment can only be symptomatic and often disappointing. In 1971 we reported the first two cases of recessive dopa-responsive dystonia, simulating a severe form of idiopathic DMD, however remarkably well reacting to levodopa treatment. We found that the first above mentioned two cases are related to mutations in the tyrosine hydroxylase gene itself in the chromosome 11p. An other variety which is dominant, with marked diurnal fluctuation, is due to mutations of a cofactor of the tyrosine hydroxylase, located in chromosome 14q. Consequently a trial of dopa treatment should be given in all diseases evoking a DMD diagnosis. Further more it is possible to confirm the diagnosis by a genetic inquiry.