Abnormal Saccades Differentiate Adolescent Onset Variant Ataxia Telangiectasia from Other Myoclonus Dystonia.
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ABSTRACT:
SUBMITTER: Cherian A
PROVIDER: S-EPMC8513963 | biostudies-literature | 2021 Jul-Aug
REPOSITORIES: biostudies-literature
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Abnormal Saccades Differentiate Adolescent Onset Variant Ataxia Telangiectasia from Other Myoclonus Dystonia.
Cherian Ajith A Chandarana Mitesh M Susvirkar Ashish Anand AA Divya K P KP Saraf Udit U UU Krishnan Syam S
Annals of Indian Academy of Neurology 20210410 4
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Project description:ObjectiveTo compare the phenotype of primary-appearing dystonia due to variant ataxia-telangiectasia (A-T) with that of other dystonia ascertained for genetics research.MethodsMovement disorder specialists examined 20 Canadian Mennonite adult probands with primary-appearing dystonia, as well as relatives in 4 families with parent-child transmission of dystonia. We screened for the exon 43 c.6200 C>A (p. A2067D) ATM mutation and mutations in DYT1 and DYT6. Clinical features of the individuals with dystonia who were harboring ATM mutations were compared with those of individuals without mutations.ResultGenetic analysis revealed a homozygous founder mutation in ATM in 13 members from 3 of the families, and no one harbored DYT6 or DYT1 mutations. Dystonia in ATM families mimicked other forms of early-onset primary torsion dystonia, especially DYT6, with prominent cervical, cranial, and brachial involvement. Mean age at onset was markedly younger in the patients with variant A-T (n = 12) than in patients with other dystonia (n = 23), (12 years vs 40 years, p < 0.05). The patients with A-T were remarkable for the absence of notable cerebellar atrophy on MRI, lack of frank ataxia on examination, and absence of ocular telangiectasias at original presentation, as well as the presence of prominent myoclonus-dystonia in 2 patients. Many also developed malignancies.ConclusionAtaxia and telangiectasias may not be prominent features of patients with variant A-T treated for dystonia in adulthood, and variant A-T may mimic primary torsion dystonia and myoclonus-dystonia.
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