title: "Jerky" dystonia in children: spectrum of phenotypes and genetic testing.
abstract: Hyperkinetic dystonia is characterized by phasic, tremulous, and "jerky" movements in addition to twisting postures. We studied longitudinally 23 index patients with hyperkinetic dystonia from a quaternary pediatric movement disorder clinic in Ireland. Four clinical categories emerged: (1) Eight patients were diagnosed with myoclonus-dystonia, of whom seven carried heterozygous epsilon sarcoglycan (SGCE) mutations, including a novel deletion of exon 10. Gait disorder, unsteadiness, or frequent falls before 18 months were detected in all SGCE mutation carriers, whereas the typical neck-predominant presentation developed only years later. (2) One patient classified as benign hereditary chorea, because jerks were choreiform and continuous rather than action-induced, carried a heterozygous stop mutation of the TITF-1 gene (Y114X, exon 2). (3) Three mutation-negative patients were grouped as "myoclonic dystonia" with jerks only in the body regions affected by dystonia. (4) Eleven patients presented with a novel combination of dystonia and low amplitude poly-mini myoclonus of the upper limbs and pectoral muscles (D-PMM). In early childhood up to 3 years of age, an initial presentation with predominant gait impairment with only subtle jerks should prompt consideration of SGCE mutation analysis in addition to testing for DYT1 mutations. A causative gene for D-PMM remains to be identified.
authors.affiliation: Department of Neurodegenerative Disease, Hertie-Institute for Clinical Brain Research, Center of Neurology, University of Tuebingen, Tuebingen, Germany.
authors.forename: Friedrich
authors.initials: F
authors.lastname: Asmus
authors.forename: Annette
authors.initials: A
authors.lastname: Langseth
authors.forename: Elaine
authors.initials: E
authors.lastname: Doherty
authors.forename: Therese
authors.initials: T
authors.lastname: Nestor
authors.forename: Marita
authors.initials: M
authors.lastname: Munz
authors.forename: Thomas
authors.initials: T
authors.lastname: Gasser
authors.forename: Tim
authors.initials: T
authors.lastname: Lynch
authors.forename: Mary D
authors.initials: MD
authors.lastname: King
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000927:Anticonvulsants / Q000627:therapeutic use; D000978:Antiparkinson Agents / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D004252:DNA Mutational Analysis; D004421:Dystonia / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy / Q000235:genetics*; D005091:Exons; D005260:Female; D005820:Genetic Testing; D005838:Genotype; D006801:Humans; D006948:Hyperkinesis / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy / Q000235:genetics*; D007980:Levodopa / Q000627:therapeutic use; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology; D009154:Mutation / Q000235:genetics; D009207:Myoclonus / Q000235:genetics / Q000503:physiopathology; D009687:Nuclear Proteins / Q000235:genetics; D010641:Phenotype; D049031:Sarcoglycans / Q000235:genetics*; D012720:Severity of Illness Index; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors / Q000235:genetics; D014443:Tyrosine / Q000235:genetics; D055815:Young Adult
chemical_list: D000927:Anticonvulsants; D000978:Antiparkinson Agents; D009687:Nuclear Proteins; C526573:SGCG protein, human; D049031:Sarcoglycans; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors; D014443:Tyrosine; D007980:Levodopa