The GNAL gene on chromosome 18 encodes a stimulatory G-alpha subunit of the G protein receptor.
Heterozygous loss-of-function mutations in the GNAL gene are known to cause isolated dystonia. Patients with heterozygous GNAL mutations typically exhibit an adult-onset focal cervical, laryngeal, and/or segmental dystonia. Homozygous or compound heterozygous GNAL mutations are associated with familial childhood-onset generalized dystonia.[PMID 27222887]