LAUSR

Dear Editor, Rapid-onset dystonia-parkinsonism (DYT/PARK-ATP1A3, formerly known as DYT12) is a combined dystonia syndrome rarely encountered in clinical practice [1]. Recent reports have expanded the clinical presentation beyond the classical phenotype and there is increasing evidence that the disease has considerable overlap with other conditions also caused by ATP1A3 mutations [2–4]. We present a new family with DYT/PARKATP1A3, highlighting the typical presenting features of this disease and describing some unusual aspects that expand the phenotype of ATP1A3 mutations. A 14-year-old girl was referred to our movement disorder clinic due to oromandibular dystonia. She was born after a normal pregnancy anddelivery; she startedwalking at 14months in a clumsy way, which motivated a Neuropediatrics consultation. At that time, myoclonus was observed affecting the upper limbs distally. She was treated with sodium valproate with improvement of the myoclonus. At age 10, she was hospitalized following a febrile illness with upper respiratory tract symptoms. Simultaneously, she developed encephalopathy, severe dysarthria, dysphagia, generalized dystonia with asymmetric upper limb involvement, bilateral myoclonus, bilateral dysmetria and ataxia. There was severe functional deterioration, including the loss of walking ability. Afterwards, she had partial recovery, during several months, with subsequent stabilization. At age 14, she maintained an action predominant generalized dystonia with greater involvement of the cranial muscles (oro-linguo-palato-laringeal dystonia), a cervical tilt and an asymmetric upper limb dystonia (video 1). The lower limbs presented minor dystonic postures. A slight bradykinesia and generalized hyporeflexia were found. She had autonomous gait. There was no rigidity, tremor, motor deficits, dysmetria or cognitive impairment. Myoclonus was not found. Her father, a 49-year-old man, was hospitalized at age 6 because of measles. At that same time, he suddenly became unable to walk, to swallow and to articulate words correctly. On the following months, he slowly regained previous function. Currently, he describes some movements as clumsy, including writing and other precision manual tasks. On neurological examination, he presents a slight dysarthria and a generalized action dystonia with predominant facial and upper limb involvement (video 1). Deep tendon reflexes are weak. There is no dysmetria, bradykinesia or rigidity. There are no other family members with similar history. Both patients were treatedwith levodopawith subjective improvement. Work-up results of the proband included a normal brain MRI and a negative DYT-TOR1A genetic test. An EEG during the hospitalization showed generalized epileptic discharges triggered by hyperventilation and photic stimulation, compatible with a myoclonic epilepsy pattern. Genetic testing by PCR amplification and Sanger sequencing revealed a heterozygous mutation in the ATP1A3 gene [c.2267G>A; (p.Arg756His)], consistent with the diagnosis of rapid-onset dystonia-parkinsonism. The father refused genetic testing. Electronic supplementary material The online version of this article (doi:10.1007/s10072-017-2996-4) contains supplementary material, which is available to authorized users.