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Background: Sequence variants in coding and noncoding regions of THAP1 have been associated with primary dystonia.Methods: In this study, 1,446 Caucasian subjects with mainly adult-onset primary dystonia and 1,520 controls were genotyped for a variant located in the 5'-untranslated region of THAP1 (c.-237_236GA>TT).Results: Minor allele frequencies were 62/2892 (2.14%) and 55/3040 (1.81%) in subjects with dystonia and controls, respectively (P=0.202). Subgroup analyses by gender and anatomical distribution also failed to attain statistical significance. In addition, there was no effect of the TT variant on expression levels of THAP1 transcript or protein.Discussion: Our findings indicate that the c.-237_236GA>TT THAP1 sequence variant does not increase risk for adult-onset primary dystonia in Caucasians. [ABSTRACT FROM AUTHOR]

Tardive syndromes (TDS) are a group of hyperkinetic and hypokinetic movement disorders that occurs after exposure to dopamine receptor blocking agents such as antipsychotic and antiemetic drugs. The Abnormal Involuntary Movement Scale (AIMS) is a widely used instrument that has become the standard for assessment of tardive dyskinesia (TDD), the most common form of TDS. However, the AIMS has a number of clinimetric limitations and was designed primarily to assess the anatomic distribution and severity of involuntary movements without regard to phenomenology. To build on recent advances in understanding and treatment of TDS, re-evaluation and revision of the AIMS that could aid both clinical practice and research may be worthwhile. Challenges, such as retaining the efficiency of the current AIMS, incorporating evaluation of impairment in daily activities, and re-training clinicians for a revised examination procedure and rating instrument, are very likely surmountable., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The vast majority of patients with primary dystonia are adults with focal or segmental distribution of involuntary movements. Although ~10% of probands have at least one first- or second-degree relative to dystonia, large families suited for linkage analysis are exceptional. After excluding mutations in known primary dystonia genes (TOR1A, THAP1 and CIZ1), whole-exome sequencing identified a GNAL missense mutation (c.682G>T, p.V228F) in an African-American pedigree with clinical phenotypes that include cervical, laryngeal and hand-forearm dystonia. Screening of 760 subjects with familial and sporadic primary dystonia identified three Caucasian pedigrees with GNAL mutations [c.591dupA (p.R198Tfs*13); c.733C>T (p.R245*); and c.3G>A (p.M1?)]. These mutations show incomplete penetrance. Our findings corroborate those of a recent study which used whole-exome sequencing to identify missense and nonsense GNAL mutations in Caucasian pedigrees of mixed European ancestry with mainly adult-onset cervical and segmental dystonia. GNAL encodes guanine nucleotide-binding protein G(olf), subunit alpha [Gα(olf)]. Gα(olf) plays a role in olfaction, coupling D1 and A2a receptors to adenylyl cyclase, and histone H3 phosphorylation. African-American subjects harboring the p.V228F mutation exhibited microsmia. Lymphoblastoid cell lines from subjects with the p.V228F mutation showed upregulation of genes involved in cell cycle control and development. Consistent with known sites of network pathology in dystonia, immunohistochemical studies indicated that Gα(olf) is highly expressed in the striatum and cerebellar Purkinje cells, and co-localized with corticotropin-releasing hormone receptors in the latter.

Background: Although the c.904_906delGAG mutation in Exon 5 of TOR1A typically manifests as early-onset generalized dystonia, DYT1 dystonia is genetically and clinically heterogeneous. Recently, another Exon 5 mutation (c.863G>A) has been associated with early-onset generalized dystonia and some DeltaGAG mutation carriers present with late-onset focal dystonia. The aim of this study was to identify TOR1A Exon 5 mutations in a large cohort of subjects with mainly non-generalized primary dystonia., Methods: High resolution melting (HRM) was used to examine the entire TOR1A Exon 5 coding sequence in 1014 subjects with primary dystonia (422 spasmodic dysphonia, 285 cervical dystonia, 67 blepharospasm, 41 writer's cramp, 16 oromandibular dystonia, 38 other primary focal dystonia, 112 segmental dystonia, 16 multifocal dystonia, and 17 generalized dystonia) and 250 controls (150 neurologically normal and 100 with other movement disorders). Diagnostic sensitivity and specificity were evaluated in an additional 8 subjects with known DeltaGAG DYT1 dystonia and 88 subjects with DeltaGAG-negative dystonia., Results: HRM of TOR1A Exon 5 showed high (100%) diagnostic sensitivity and specificity. HRM was rapid and economical. HRM reliably differentiated the TOR1A DeltaGAG and c.863G>A mutations. Melting curves were normal in 250/250 controls and 1012/1014 subjects with primary dystonia. The two subjects with shifted melting curves were found to harbor the classic DeltaGAG deletion: 1) a non-Jewish Caucasian female with childhood-onset multifocal dystonia and 2) an Ashkenazi Jewish female with adolescent-onset spasmodic dysphonia., Conclusion: First, HRM is an inexpensive, diagnostically sensitive and specific, high-throughput method for mutation discovery. Second, Exon 5 mutations in TOR1A are rarely associated with non-generalized primary dystonia.

Tremor is defined as involuntary rhythmic oscillation and is produced by muscle contractions. Hemifacial spasm is rapid involuntary muscle contractions on one side of the face in the distribution of the VIIth nerve. We present a severe case of hemifacial spasm that produces a head-nodding tremor-like movements.

The DeltaGAG deletion mutation in DYT1, causing a loss of a glutamic acid near the carboxyl terminus of torsinA protein (torsinADeltaE), is dominantly inherited and tends to result in a severe generalized form of dystonia with childhood onset. We have used a yeast two-hybrid interaction assay to examine torsinA and its mutant torsinADeltaE interactions. Our data showed that torsinA monomers are capable of interacting with themselves and that mutant torsinADeltaE fails to interact with itself or with torsinA. We also demonstrated that purified torsinA protein is an ATPase, which forms a multimeric complex in vitro and that the DeltaGAG mutation disrupts the formation of multimeric complex and decreases torsinA's ATPase activity.

We studied a case series of 9 patients with posttraumatic cervical dystonia, in whom involuntary muscle spasms and abnormal head postures occurred within 7 days after cervical injury. Patients were examined, treated with botulinum toxin as necessary, and were followed up to 5 years. Based on our observations of these cases, we propose that complex regional pain syndrome (CRPS) could represent a variant of posttraumatic cervical dystonia that may develop over time after the initiation of dystonia., (2004 Movement Disorder Society.)

Background: Mucolipidosis type IV (MLIV) is an autosomal recessive disease caused by mutations in the MCOLN1 gene that codes for mucolipin, a member of the transient receptor potential (TRP) gene family., Objective: To comprehensively characterize the clinical and genetic abnormalities of MLIV., Methods: Twenty-eight patients with MLIV, aged 2 to 25 years, were studied. Ten returned for follow-up every 1 to 2 years for up to 5 years. Standard clinical, neuroimaging, neurophysiologic, and genetic techniques were used., Results: All patients had varying degrees of corneal clouding, with progressive optic atrophy and retinal dystrophy. Twenty-three patients had severe motor and mental impairment. Motor function deteriorated in three patients and remained stable in the rest. All had a constitutive achlorhydria with elevated plasma gastrin level, and 12 had iron deficiency or anemia. Head MRI showed consistent characteristic findings of a thin corpus callosum and remained unchanged during the follow-up period. Prominent abnormalities of speech, hand usage, and swallowing were also noted. Mutations in the MCOLN1 gene were present in all patients. Correlation of the genotype with the neurologic handicap and corpus callosum dysplasia was found., Conclusions: MLIV is both a developmental and a degenerative disorder. The presentation as a cerebral palsy-like encephalopathy may delay diagnosis.

Background and Purpose: Fabry disease is an X-linked inherited disorder resulting from a deficiency of alpha-galactosidase A. Cerebrovascular disease in Fabry disease includes small-vessel disease and larger-vessel ectasia in a predominantly posterior distribution. We assessed transcranial Doppler (TCD) blood flow velocities in naive and enzyme-treated Fabry patients., Methods: TCD was used to noninvasively examine patients with Fabry disease for abnormal cerebral blood flow velocities. TCD measurements were also made during CO2 retention by breathholding to examine cerebrovascular vessel reactivity. Twenty-six patients were enrolled in a 6-month, double-blind, placebo-controlled trial of enzyme replacement therapy consisting of biweekly intravenous alpha-galactosidase A infusions, with a subsequent 18-month follow-up in an open-label trial. Statistical analysis consisted of applying a mixed-effects ANOVA model for correlated outcomes., Results: Peak velocity, mean velocity, pulsatility index, and resistance index were found to be significantly higher in patients compared with control subjects. When the individual vessels were considered, elevated flow velocities were found in the middle cerebral M1 branch and the posterior cerebral artery. Enzyme replacement therapy significantly decreased peak, mean, and end-diastolic velocities and flow acceleration at the 18-month follow-up time point., Conclusions: Patients with Fabry disease have elevated cerebral blood flow velocities. These velocities significantly improved with enzyme replacement therapy.

Objective: The objective of this study is to characterize the brain abnormalities on head MRI of patients with mucolipidosis type IV., Background: Mucolipidosis type IV is an autosomal recessive lysosomal storage disease of unknown etiology. Patients develop corneal clouding, retinal degeneration, spastic quadriparesis, and mental retardation. Patients with this disorder have not been studied systematically., Methods: We studied prospectively 15 consecutive patients with mucolipidosis type IV using cranial MRI., Results: Fourteen patients with these typical clinical findings had a hypoplastic corpus callosum with absent rostrum and a dysplastic or absent splenium, signal abnormalities on T1-weighted head MRI images in the white matter, and increased ferritin deposition in the thalamus and basal ganglia. Atrophy of the cerebellum and cerebrum was observed in older patients, which may reflect disease progression. One patient with a mild clinical variant had a normal corpus callosum., Conclusion: Patients with mucolipidosis type IV have characteristic cranial MRI findings that suggest that this disorder causes both developmental and neurodegenerative abnormalities.

Objective: This study's purpose was to obtain a quantitative natural history of the cerebrovascular involvement in Fabry disease., Background: Fabry disease is an X-linked recessive disorder due to alpha-galactosidase A deficiency. Progressive accumulation of ceramidetrihexoside within the intima and media of cerebral blood vessels causes ischemic lesions in the majority of affected patients. Determination of the natural history of the cerebral vasculopathy in Fabry disease is important to assess the effects of therapeutic intervention in this disorder., Methods: A longitudinal MRI study of 50 patients who had a total of 129 MRI scans was performed. The burden of cerebrovascular disease was determined using direct linear measurement., Results: On T2-weighted MRI scans, 32% of the patients had no lesions (mean age, 33 years), 16% had gray matter lesions only (mean age, 36 years), 26% had lesions in white matter only (mean age, 43 years), and 26% had lesions in white and gray matter (mean age, 47 years). Disease burden increased with age, but no patient younger than 26 had lesions on MRI. All patients older than 54 had cerebrovascular involvement. The distribution of MRI-detectable lesions was typical of a small-vessel disease. Only 37.5% of patients with cerebral lesions had neurologic symptoms., Conclusion: These findings provide a predictable outcome measure to assess the effect of molecular interventions on the cerebrovascular circulation in Fabry disease.

Mucolipidosis type IV is an autosomal recessive lysosomal storage disease of unknown etiology that causes severe neurological and ophthalmological abnormalities. In an attempt to obtain insight into the nature of the metabolic abnormality in this disorder, we prospectively evaluated 15 consecutive patients, aged 2 to 23 years, over a period of 22 months. The finding of iron deficiency in some of the patients led us to the discovery that all patients but one had markedly elevated blood gastrin levels. None had vitamin B12 deficiency. Gastroscopy in three patients showed normal gross appearance of the mucosa in two patients, 4 and 7 years old, and mucosal atrophy in a 22-year-old. Parietal cells were present in normal numbers and contained large cytoplasmic inclusions that were confirmed immunohistochemically to be lysosomal in nature. Other gastric epithelial cells appeared normal. Parietal cells contained very few tubulovesicular membranes, suggesting cellular activation, whereas apical canaliculi appeared relatively nonactivated. Both subunits of the parietal cell H+/K+-ATPase were present, and both partially colocalized with f-actin at the apical membrane. We conclude that patients with mucolipidosis type IV are constitutively achlorhydric and have partially activated parietal cells. We hypothesize that the defective protein in this disease is closely associated with the final stages of parietal cell activation and is critical for a specific type of cellular vacuolar trafficking between the cytoplasm and the apical membrane domain.