ADCY5-related dyskinesias: An amalgamation of various hyperkinetic movement disorders

Abstract

Abstract Adenylyl cyclase 5 (ADCY5)-related dyskinesia is a rare disorder characterized by early-onset paroxysmal choreoathetosis, dystonia, myoclonus, or a combination thereof, primarily involving the limbs, face, and neck. Other core clinical features include nocturnal ballistic bouts and facial dyskinesias, often followed by remission during adolescence, as well as axial hypotonia. Any mixed movement disorder accompanied by the aforementioned core features should prompt genetic testing for ADCY5 mutation. We report the case of a 31-year man from North India with a childhood-onset history of clumsy, random, and jerky body and facial movements, interfering with his speech and object-handling and walking-related functional abilities. He improved symptomatically with zonisamide and was offered caffeine as a maintenance option. Here, we review the literature on this entity, while reporting this first case of ADCY5-related dyskinesias from North India. The phenotypic spectrum linked to ADCY5 mutations has significantly broadened since its initial description in a family with “familial dyskinesia and facial myokymia.” This phenotypic variability could be responsible for a proportion of “idiopathic” hyperkinetic movement disorders. Gaining a better understanding of its clinical manifestations helps in identifying complex or uncommon cases more effectively.