Focal dystonia, the most common form of dystonia, is often task-specific and referred to as FTSD. Specific learned motor tasks, such as writing or playing a musical instrument, can trigger muscle spasms and interfere with performance while other ... Focal dystonia, the most common form of dystonia, is often task-specific and referred to as FTSD. Specific learned motor tasks, such as writing or playing a musical instrument, can trigger muscle spasms and interfere with performance while other actions are unaffected. FTSD has a frequency of 1 in 3,400 in the general population but increases to 1 in 200 among musicians (Pullman and Hristova, 2005).
Schmidt et al. (2006) reported 3 unrelated families in which the proband presented with musician's dystonia: 1 pianist and 2 guitarists. All probands had 2 or 3 family members with other forms of focal dystonia, mainly writer's cramp ... Schmidt et al. (2006) reported 3 unrelated families in which the proband presented with musician's dystonia: 1 pianist and 2 guitarists. All probands had 2 or 3 family members with other forms of focal dystonia, mainly writer's cramp and 1 case of 'handicraft' dystonia while threading needles. Inheritance in all families was consistent with autosomal dominant. All but 1 affected individuals had onset of dystonia in the third or fourth decade. Two affected family members were professional musicians, but had only writer's cramp and no musician's dystonia. Conversely, 1 of the probands had both musician's dystonia and writer's cramp. The disorder was triggered by increased practice in about half of the affected individuals. All had an upper limb dystonia, and none carried common DYT1 mutations (TOR1A; 605204). Schmidt et al. (2006) concluded that musician's dystonia is not necessarily a sporadic condition and that there is a genetic contribution to focal task-specific dystonia with phenotypic variability, including musician's dystonia.