Browsing by Author "Hagenah, Johann (6701387839)"

Objective: To evaluate the frequency and clinical spectrum of the recently identified p.D620N mutation in the VPS35 gene in Parkinson disease (PD) in an international sample. Design: Genetic analysis by DNA sequencing and detailed clinical and neuropsychiatric assessment as well as neuroimaging in mutation carriers. Setting: Tertiary referral centers in Germany, Serbia, Chile, and the United States. Patients: One thousand seven hundred seventy-four patients with PD. Main Outcome Measure: Frequency of the p.D620N mutation. Results: A single mutation carrier was identified. The mutation carrier was a 60-year-old German man who had tremor-dominant PD since the age of 45 years. Longitudinal follow-up over 13 years revealed a disease progression from Hoehn and Yahr stage 1 to 3. There was evidence of mild cognitive impairment on the Montreal Cognitive Assessment. No abnormalities were observed by multimodal neuroimaging. He had a family history consistent with autosomal dominant inheritance. An affected paternal aunt and 3 reportedly unaffected siblings were also found to be mutation carriers. Conclusion: VPS35 mutations are a rare cause of PD in different populations. The clinical phenotype may be indistinguishable from idiopathic PD with the possible exception of an earlier age at onset. Genetic analysis of the extended family revealed incomplete penetrance of the p.D620N mutation. ©2012 American Medical Association. All rights reserved.

Objective: To evaluate the frequency and clinical spectrum of the recently identified p.D620N mutation in the VPS35 gene in Parkinson disease (PD) in an international sample. Design: Genetic analysis by DNA sequencing and detailed clinical and neuropsychiatric assessment as well as neuroimaging in mutation carriers. Setting: Tertiary referral centers in Germany, Serbia, Chile, and the United States. Patients: One thousand seven hundred seventy-four patients with PD. Main Outcome Measure: Frequency of the p.D620N mutation. Results: A single mutation carrier was identified. The mutation carrier was a 60-year-old German man who had tremor-dominant PD since the age of 45 years. Longitudinal follow-up over 13 years revealed a disease progression from Hoehn and Yahr stage 1 to 3. There was evidence of mild cognitive impairment on the Montreal Cognitive Assessment. No abnormalities were observed by multimodal neuroimaging. He had a family history consistent with autosomal dominant inheritance. An affected paternal aunt and 3 reportedly unaffected siblings were also found to be mutation carriers. Conclusion: VPS35 mutations are a rare cause of PD in different populations. The clinical phenotype may be indistinguishable from idiopathic PD with the possible exception of an earlier age at onset. Genetic analysis of the extended family revealed incomplete penetrance of the p.D620N mutation. ©2012 American Medical Association. All rights reserved.

IMPORTANCE: Mutations in the GNAL gene have recently been shown to cause primary torsion dystonia. The GNAL-encoded protein (Gαolf) is important for dopamine D1receptor function and odorant signal transduction.We sequenced all 12 exons of GNAL in 461 patients from Germany, Serbia, and Japan, including 318 patients with dystonia (190 with cervical dystonia), 51 with hyposmia and Parkinson disease, and 92 with tardive dyskinesia or acute dystonic reactions. OBSERVATIONS: We identified the following two novel heterozygous putative mutations in GNAL: p.Gly213Ser in a German patient and p.Ala353Thr in a Japanese patient. These variants were predicted to be pathogenic in silico,were absent in ethnically matched control individuals, and impaired Gαolfcoupling to D1receptors in a bioluminescence energy transfer (BRET) assay. Two additional variants appeared to be benign because they behaved like wild-type samples in the BRET assay (p.Ala311Thr) or were detected in ethnically matched controls (p.Thr92Ala). Both patients with likely pathogenic mutations had craniocervical dystonia with onset in the fifth decade of life. No pathogenic mutations were detected in the patients with hyposmia and Parkinson disease, tardive dyskinesias, or acute dystonic reactions. CONCLUSIONS AND RELEVANCE: Mutations in GNAL can cause craniocervical dystonia in different ethnicities. The BRET assaymay be a useful tool to support the pathogenicity of identified variants in the GNAL gene. Copyright 2014 American Medical Association. All rights reserved.

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Objective: A study was undertaken to identify the gene underlying DYT4 dystonia, a dominantly inherited form of spasmodic dysphonia combined with other focal or generalized dystonia and a characteristic facies and body habitus, in an Australian family. Methods: Genome-wide linkage analysis was carried out in 14 family members followed by genome sequencing in 2 individuals. The index patient underwent a detailed neurological follow-up examination, including electrophysiological studies and magnetic resonance imaging scanning. Biopsies of the skin and olfactory mucosa were obtained, and expression levels of TUBB4 mRNA were determined by quantitative real-time polymerase chain reaction in 3 different cell types. All exons of TUBB4 were screened for mutations in 394 unrelated dystonia patients. Results: The disease-causing gene was mapped to a 23cM region on chromosome 19p13.3-p13.2 with a maximum multipoint LOD score of 5.338 at markers D9S427 and D9S1034. Genome sequencing revealed a missense variant in the TUBB4 (tubulin beta-4; Arg2Gly) gene as the likely cause of disease. Sequencing of TUBB4 in 394 unrelated dystonia patients revealed another missense variant (Ala271Thr) in a familial case of segmental dystonia with spasmodic dysphonia. mRNA expression studies demonstrated significantly reduced levels of mutant TUBB4 mRNA in different cell types from a heterozygous Arg2Gly mutation carrier compared to controls. Interpretation: A mutation in TUBB4 causes DYT4 dystonia in this Australian family with so-called whispering dysphonia, and other mutations in TUBB4 may contribute to spasmodic dysphonia. Given that TUBB4 is a neuronally expressed tubulin, our results imply abnormal microtubule function as a novel mechanism in the pathophysiology of dystonia. © 2013 American Neurological Association.

Objective: A study was undertaken to identify the gene underlying DYT4 dystonia, a dominantly inherited form of spasmodic dysphonia combined with other focal or generalized dystonia and a characteristic facies and body habitus, in an Australian family. Methods: Genome-wide linkage analysis was carried out in 14 family members followed by genome sequencing in 2 individuals. The index patient underwent a detailed neurological follow-up examination, including electrophysiological studies and magnetic resonance imaging scanning. Biopsies of the skin and olfactory mucosa were obtained, and expression levels of TUBB4 mRNA were determined by quantitative real-time polymerase chain reaction in 3 different cell types. All exons of TUBB4 were screened for mutations in 394 unrelated dystonia patients. Results: The disease-causing gene was mapped to a 23cM region on chromosome 19p13.3-p13.2 with a maximum multipoint LOD score of 5.338 at markers D9S427 and D9S1034. Genome sequencing revealed a missense variant in the TUBB4 (tubulin beta-4; Arg2Gly) gene as the likely cause of disease. Sequencing of TUBB4 in 394 unrelated dystonia patients revealed another missense variant (Ala271Thr) in a familial case of segmental dystonia with spasmodic dysphonia. mRNA expression studies demonstrated significantly reduced levels of mutant TUBB4 mRNA in different cell types from a heterozygous Arg2Gly mutation carrier compared to controls. Interpretation: A mutation in TUBB4 causes DYT4 dystonia in this Australian family with so-called whispering dysphonia, and other mutations in TUBB4 may contribute to spasmodic dysphonia. Given that TUBB4 is a neuronally expressed tubulin, our results imply abnormal microtubule function as a novel mechanism in the pathophysiology of dystonia. © 2013 American Neurological Association.