Dystonia 25

DYT-GNAL caused by a heterozygous GNAL pathogenic variant has been reported in more than 60 individuals to date. It is characterized by adult-onset isolated dystonia (i.e., no neurologic abnormalities other than tremor are evident on neurologic examination). The dystonia is most commonly focal and segmental, and rarely generalized. Dystonia is typically cervical in onset and commonly progresses to the cranial region (oromandibular/jaw, larynx, eyelids) and/or to one arm. Tremor reported in DYT-GNAL may be dystonic (i.e., occurring in a body part that shows at least minimal signs of dystonia) and may precede or follow the onset of dystonia. Intra- and interfamilial variability is considerable. DYT-GNAL caused by biallelic GNAL pathogenic variants, reported to date in two sibs from a consanguineous family, is characterized by mild intellectual disability and childhood-onset hypertonia that progresses to generalized dystonia. [from GeneReviews]