The clinical phenotype of early-onset isolated dystonia caused by recessive COL6A3 mutations (DYT27)

Background and PurposeWe recently identified mutations in the a3 (VI) collagen gene COL6A3 that cause autosomal-recessive isolated dystonia (DYT27). This article gives a detailed description of the clinical phenotype associated with this new type of dystonia. MethodsA total of 5 recessive COL6A3 mutation carriers underwent clinical examinations, and case histories were recorded on videotape. ResultsBiallelic COL6A3 mutations cause isolated dystonia with interindividual heterogeneity of distribution and severity. Dystonia was generalized in 3 patients, pronounced in the cranio-cervical region, upper limbs, and trunk; segmental in 1 patient, with the neck and upper limbs affected; and focal with cervical involvement in another patient. Symptoms began in childhood, adolescence, or early adulthood, initially affecting the neck as cervical dystonia or the hand as writer's cramp. ConclusionCOL6A3-associated dystonia represents a newly identified autosomal-recessive entity characterized clinically by an early symptom onset with variable distribution. (c) 2015 Movement Disorder Society