title: Myoclonic axial jerks for diagnosing atypical evolution of ataxia telangiectasia.
abstract: BACKGROUND
  Ataxia telangiectasia (A-T) is a common inherited cause of early childhood-onset ataxia, distinguished by progressive cerebellum malfunction, capillary vessel extension, and immunodeficiency. The diagnosis of A-T is sometimes difficult to establish in patients with atypical clinical evolution.
  
  
  METHODS
  We experienced a pediatric 12-years-old female patient, who was finally diagnosed with classic A-T, demonstrating progressive dystonic-myoclonic axial jerks with ataxia as a predominant clinical feature. Oculocutaneous telangiectasias and immune status were unremarkable. Her myoclonic jerks were spontaneous or stimulus-sensitive, and partially ameliorated by levodopa treatment, but the ataxia was slowly progressive. A laboratory examination showed moderate atrophy of the vermis and cerebellum on brain magnetic resonance imaging, elevated serum alpha fetoprotein (AFP) levels, and total absence of A-T mutated (ATM) protein activity. We subsequently confirmed compound heterozygous truncating mutations of the ATM gene in this patient.
  
  
  CONCLUSIONS
  Our findings highlight the importance of recognizing dystonic-myoclonic jerks as one of the extrapyramidal signs of classic A-T. Measurement of AFP levels should be considered in patients with unexplained myoclonic jerk movements with ataxia in whom definitive diagnoses are not identified. Physicians should be aware that there are cases where typical findings of A-T may not be fulfilled.
authors: Department of Pediatrics, Tohoku University School of Medicine, Aoba-ku, Sendai, Japan. Electronic address: tojo-nakayama@umin.ac.jp.
authors: Tojo
authors: T
authors: Nakayama
authors: Department of Pediatrics, Tohoku University School of Medicine, Aoba-ku, Sendai, Japan.
authors: Yuko
authors: Y
authors: Sato
authors: Department of Pediatrics, Tohoku University School of Medicine, Aoba-ku, Sendai, Japan.
authors: Mitsugu
authors: M
authors: Uematsu
authors: Department of the Pediatrics and Developmental Biology, Tokyo Medical and Dental University, Japan.
authors: Masatoshi
authors: M
authors: Takagi
authors: Department of the Pediatrics and Developmental Biology, Tokyo Medical and Dental University, Japan.
authors: Setsuko
authors: S
authors: Hasegawa
authors: Department of Neuropediatrics, Tokyo Metropolitan Neurological Hospital, Japan.
authors: Satoko
authors: S
authors: Kumada
authors: Department of Pediatrics, Tohoku University School of Medicine, Aoba-ku, Sendai, Japan.
authors: Atsuo
authors: A
authors: Kikuchi
authors: Department of Pediatrics, Tohoku University School of Medicine, Aoba-ku, Sendai, Japan.
authors: Naomi
authors: N
authors: Hino-Fukuyo
authors: Department of Pediatrics, Tohoku University School of Medicine, Aoba-ku, Sendai, Japan.
authors: Yoji
authors: Y
authors: Sasahara
authors: Department of Pediatrics, Tohoku University School of Medicine, Aoba-ku, Sendai, Japan; Department of Pediatric Neurology, Takuto Rehabilitation Center for Children, Japan.
authors: Kazuhiro
authors: K
authors: Haginoya
authors: Department of Pediatrics, Tohoku University School of Medicine, Aoba-ku, Sendai, Japan.
authors: Shigeo
authors: S
authors: Kure
mesh_terms: D001260:Ataxia Telangiectasia / Q000150:complications* / Q000175:diagnosis*; D002648:Child; D005260:Female; D006801:Humans; D009207:Myoclonus / Q000209:etiology*
keywords: AFP; ATM gene; Ataxia telangiectasia; Extrapyramidal sign; Myoclonic jerk