An autosomal dominant familial dyskinesia gene: ADCY5 mutation

The ADCY5 gene has an important role in intracellular signaling pathways.Its mutation causes 'dyskinesia with orofacial involvement'. It is an autosomal dominant inherited disease characterized by hyperkinetic movement disorder. The onset of the disease can range from infancy to adolescence. There are episodes of choreiform, myoclonic, and dystonic movement in the extremities, face, and neck. Sleep, stress, anxiety, caffeine intake are the triggering factors. A 4-year-old male patient was admitted to our outpatient clinic with complaints of inability to walk and dystonia, which is mostly nocturnal, awakening from sleep. It was learned that the patient had been followed up in another center for hypotonia, growth retardation and movement disorder since he was 9 months old. Routine laboratory tests, metabolic tests and cranial magnetic resonance imaging were normal. In the whole exome analysis, heterozygous c.1252C>T mutation was detected in the ADCY5 gene and the patient was diagnosed with ‘dyskinesia with orofacial involvement’. Since this mutation was not found in his parents, it was evaluated as de novo. The patient was started on clonazepam treatment. The patient, who could not walk without support before the treatment, became able to walk a short distance without support after the treatment. In addition, the number of dystonias, which wakes the patient from sleep approximately 20 times, has decreased to 5-6 times a night. ADCY5 mutations should be kept in mind in patients with early-onset hypotonia and movement disorder. Clonazepam may be effective in symptomatic treatment.
Keywords: ADCY5 gene, dyskinesia, dystonia, hyperkinetic movement disorder, hypotonia, myokymia