Project description:Background and objectivesRapid-onset dystonia-parkinsonism (RDP) is caused by mutations in the ATP1A3 gene, which codes for the α-3 subunit of the Na+ /K+ ATPase. It has been characterized by rapid-onset bulbar dysfunction, limb dystonia, bradykinesia, and a rostrocaudal spatial gradient of expression, usually after a physiologic trigger. We reexamined whether these features were in fact characteristic.MethodsWe characterized phenotypic variation within a cohort of 50 ATP1A3 mutation-positive individuals (carriers) and 44 mutation-negative family members (noncarriers). Potential participants were gathered through referral for clinical suspicion of RDP or alternating hemiplegia of childhood. Inclusion criteria were having a ATP1A3 mutation or being a family member of such an individual.ResultsWe found RDP is underdiagnosed if only "characteristic" patients are tested. Rapid onset and bulbar predominance were not universally present in carriers. Among those with at least mild symptoms of dystonia, rostrocaudal severity gradient was rare (7%). Symptoms began focally but progressed to be generalized (51%) or multifocal (49%). Arm (41%) onset was most common. Arms and voice were typically most severely affected (48% and 44%, respectively). Triggers preceded onset in 77% of the participants. Rapid onset, dystonia, parkinsonism, bulbar symptoms, headaches, seizures, frontal impairment, and a history of mood disorder and a history of psychosis were more common in carriers. Approximately half of the proband mutations occurred de novo (56%).ConclusionsOur findings suggest that patients should not be excluded from ATP1A3 testing because of slow onset, limb onset, absent family history, or onset in middle adulthood. RDP should be strongly considered in the differential for any bulbar dystonia. © 2019 International Parkinson and Movement Disorder Society.

| S-EPMC6879786 | biostudies-literature

ATP1A3 mutation in rapid-onset dystonia parkinsonism: New data and genotype-phenotype correlation analysis.

Project description:BackgroundRapid-onset dystonia parkinsonism (RDP) is a rare disease caused by ATP1A3 mutation with considerable clinical heterogeneity. Increased knowledge of RDP could be beneficial in its early diagnosis and treatment.ObjectiveThis study aimed to summarize the gene mutation spectrum of ATP1A3 associated with RDP, and to explore the correlation of ATP1A3 variants with RDP clinical phenotypes.MethodsIn this study, we reported two RDP patients from a family with a novel inherited ATP1A3 variant. Then, we reviewed and analyzed the available literature in English focused on ATP1A3-causative RDP. A total of 35 articles covering 15 families (59 patients) and 36 sporadic RDP cases were included in our analysis.ResultsThe variant A813V (2438C>T) in ATP1A3 found in our cases was a novel mutant. Delays in diagnosis were common, with a mean delay time of 14 years. ATP1A3 had distinct RDP-related mutation hotspots, which consisted of exon8, 14, 17, and 18, and the most frequently occurring variants were T613M and I578S. Approximately 74.5% of patients have specific triggers before disease onset, and 82.1% of RDPs have stable symptoms within 1 month. The incidence rates of dystonia and bradykinesia are 100 and 88.1%, respectively. The onset site varied and exhibited a rostrocaudal gradient distribution pattern in 45% of patients with RDP. Approximately 63.6% of patients had mild improvement after receiving comprehensive interventions, especially in gait disturbance amelioration.ConclusionIn patients with acute and unexplained dystonia or bradykinesia, gene screening on ATP1A3 should be timely performed. When a diagnosis has been made, treatments that may be effective are to be attempted. Our study would be helpful for the early diagnosis and treatment of ATP1T3-related RDP.

| S-EPMC9376385 | biostudies-literature

Characterization of Atp1a3 mutant mice as a model of rapid-onset dystonia with parkinsonism.

Project description:Rapid-onset dystonia with parkinsonism (RDP) or DYT12 dystonia is a rare form of primary, generalized dystonia. Patients do not present with any symptoms until triggered by a physiological stressor. Within days, patients will show both dystonia and parkinsonism. Mutations resulting in a loss of function in the ATP1A3 gene have been identified as the cause of RDP. ATP1A3 encodes the ?3 subunit of the Na(+)/K(+)-ATPase, which is exclusively expressed in neurons and cardiac cells. We have previously created a line of mice harboring a point mutation of the Atp1a3 gene (mouse homolog of the human ATP1A3 gene) that results in a loss of function of the ?3 subunit. The Atp1a3 mutant mice showed hyperactivity, spatial learning and memory deficits, and increased locomotion induced by methamphetamine. However, the full spectrum of the motor phenotype has not been characterized in the mutant mice and it is not known whether triggers such as restraint stress affect the motor phenotype. Here, we characterized the motor phenotype in normal heterozygous Atp1a3 mutant mice and heterozygous Atp1a3 mutant mice that have been exposed to a restraint stress. We found that this type of trigger induced significant deficits in motor coordination and balance in the mutant mice, characteristic of other genotypic dystonia mouse models. Furthermore, stressed mutant mice also had a decreased thermal sensitivity and alterations in monoamine metabolism. These results suggest that the Atp1a3 mutant mouse models several characteristics of RDP and further analysis of this mouse model will provide great insight into pathogenesis of RDP.

| S-EPMC2981691 | biostudies-literature

Basal Ganglia Gliosis in a Case of Rapid-Onset Dystonia-Parkinsonism (DYT12) with a Novel Mutation in ATPase 1A3 (ATP1A3).

Project description: Not available

| S-EPMC6353479 | biostudies-literature

A novel de novo mutation in ATP1A3 and childhood-onset schizophrenia.

Project description:We describe a child with onset of command auditory hallucinations and behavioral regression at 6 yr of age in the context of longer standing selective mutism, aggression, and mild motor delays. His genetic evaluation included chromosomal microarray analysis and whole-exome sequencing. Sequencing revealed a previously unreported heterozygous de novo mutation c.385G>A in ATP1A3, predicted to result in a p.V129M amino acid change. This gene codes for a neuron-specific isoform of the catalytic α-subunit of the ATP-dependent transmembrane sodium-potassium pump. Heterozygous mutations in this gene have been reported as causing both sporadic and inherited forms of alternating hemiplegia of childhood and rapid-onset dystonia parkinsonism. We discuss the literature on phenotypes associated with known variants in ATP1A3, examine past functional studies of the role of ATP1A3 in neuronal function, and describe a novel clinical presentation associated with mutation of this gene.

| S-EPMC5002930 | biostudies-literature

Rapid-onset dystonia-parkinsonism associated with the I758S mutation of the ATP1A3 gene: a neuropathologic and neuroanatomical study of four siblings.

Project description:Rapid-onset dystonia-parkinsonism (RDP) is a movement disorder associated with mutations in the ATP1A3 gene. Signs and symptoms of RDP commonly occur in adolescence or early adulthood and can be triggered by physical or psychological stress. Mutations in ATP1A3 are also associated with alternating hemiplegia of childhood (AHC). The neuropathologic substrate of these conditions is unknown. The central nervous system of four siblings, three affected by RDP and one asymptomatic, all carrying the I758S mutation in the ATP1A3 gene, was analyzed. This neuropathologic study is the first carried out in ATP1A3 mutation carriers, whether affected by RDP or AHC. Symptoms began in the third decade of life for two subjects and in the fifth for another. The present investigation aimed at identifying, in mutation carriers, anatomical areas potentially affected and contributing to RDP pathogenesis. Comorbid conditions, including cerebrovascular disease and Alzheimer disease, were evident in all subjects. We evaluated areas that may be relevant to RDP separately from those affected by the comorbid conditions. Anatomical areas identified as potential targets of I758S mutation were globus pallidus, subthalamic nucleus, red nucleus, inferior olivary nucleus, cerebellar Purkinje and granule cell layers, and dentate nucleus. Involvement of subcortical white matter tracts was also evident. Furthermore, in the spinal cord, a loss of dorsal column fibers was noted. This study has identified RDP-associated pathology in neuronal populations, which are part of complex motor and sensory loops. Their involvement would cause an interruption of cerebral and cerebellar connections which are essential for maintenance of motor control.

| S-EPMC4059967 | biostudies-literature

ATP1A3 mutations in infants: a new rapid-onset dystonia-Parkinsonism phenotype characterized by motor delay and ataxia.

Project description:We report new clinical features of delayed motor development, hypotonia, and ataxia in two young children with mutations (R756H and D923N) in the ATP1A3 gene. In adults, mutations in ATP1A3 cause rapid-onset dystonia-Parkinsonism (RDP, DYT12) with abrupt onset of fixed dystonia. The parents and children were examined and videotaped, and samples were collected for mutation analysis. Case 1 presented with fluctuating spells of hypotonia, dysphagia, mutism, dystonia, and ataxia at 9 months. After three episodes of hypotonia, she developed ataxia, inability to speak or swallow, and eventual seizures. Case 2 presented with hypotonia at 14 months and pre-existing motor delay. At age 4 years, he had episodic slurred speech, followed by ataxia, drooling, and dysarthria. He remains mute. Both children had ATP1A3 gene mutations. To our knowledge, these are the earliest presentations of RDP, both with fluctuating features. Both children were initially misdiagnosed. RDP should be considered in children with discoordinated gait, and speech and swallowing difficulties.

| S-EPMC3465467 | biostudies-literature

ATP1A3 Mutation in Adult Rapid-Onset Ataxia.

Project description:A 21-year old male presented with ataxia and dysarthria that had appeared over a period of months. Exome sequencing identified a de novo missense variant in ATP1A3, the gene encoding the α3 subunit of Na,K-ATPase. Several lines of evidence suggest that the variant is causative. ATP1A3 mutations can cause rapid-onset dystonia-parkinsonism (RDP) with a similar age and speed of onset, as well as severe diseases of infancy. The patient's ATP1A3 p.Gly316Ser mutation was validated in the laboratory by the impaired ability of the expressed protein to support the growth of cultured cells. In a crystal structure of Na,K-ATPase, the mutated amino acid was directly apposed to a different amino acid mutated in RDP. Clinical evaluation showed that the patient had many characteristics of RDP, however he had minimal fixed dystonia, a defining symptom of RDP. Successive magnetic resonance imaging (MRI) revealed progressive cerebellar atrophy, explaining the ataxia. The absence of dystonia in the presence of other RDP symptoms corroborates other evidence that the cerebellum contributes importantly to dystonia pathophysiology. We discuss the possibility that a second de novo variant, in ubiquilin 4 (UBQLN4), a ubiquitin pathway component, contributed to the cerebellar neurodegenerative phenotype and differentiated the disease from other manifestations of ATP1A3 mutations. We also show that a homozygous variant in GPRIN1 (G protein-regulated inducer of neurite outgrowth 1) deletes a motif with multiple copies and is unlikely to be causative.

| S-EPMC4798776 | biostudies-literature

Rapid-Onset Dystonia-Parkinsonism Phenotype Consistency for a Novel Variant of ATP1A3 in Patients Across 3 Global Populations.

Project description: Not available

| S-EPMC8105889 | biostudies-literature