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Título

SPINOCEREBELLAR ATAXIA TYPE 2 (SCA2) WITH CLINICAL ONSET IN CHILDHOOD

Apresentação do caso único

A 12-year-old female patient was brought for evaluation with family complaints of progressive imbalance, gait instability, frequent falls and slurred speech that started at the age of 3. Prior to that age, the neurodevelopment showed no abnormalities. She also had difficulty performing basic activities of daily living, such as feeding using utensils and experienced episodes of pain and muscle contractions during sleep. Myoclonic jerks initially triggered by stimuli were also reported. At the age of 7, she lost the ability to walk. At the age of 8, she started experiencing daily paroxysmal episodes of tonic limb posturing and sphincter release. At the age of 9, language regression with dysarthria and decreased vocabulary were observed. At the same age, upper limb motor incoordination and loss of writing ability were noted. At 10 years of age, due to worsening dysphagia and significant malnutrition, a gastrostomy was performed. At the same time, the patient progressed with urinary and fecal incontinence, requiring the use of diapers. Neurological examination at 12 years old revealed facial weakness, horizontal gaze palsy, flaccid areflexic tetraparesis, with dystonic movements. The patient was nonverbal and unable to ambulate or tolerate orthostasis. Continuous EEG revealed frequent bursts of slow waves, predominantly during sleep, frequent generalized epileptiform activity and frequent bilateral frontotemporal epileptiform activity. During the conventional EEG exam, the patient presented episodes of generalized myoclonus. Brain MRI showed diffuse cerebral and cerebellar atrophy, and an area of T2/FLAIR white matter hyperintensity in the right frontal lobe. The patient had a healthy 2-year-old sister and a 48-year-old ambulatory father with family reports of gait instability. It was later found that the father had the diagnosis of Spinocerebellar Ataxia type 2 (SCA2). Molecular genetic testing of the patient confirmed the diagnosis of SCA2, with 66 CAG trinucleotide repeat expansion in ATXN2 gene.

Discussão

Clinical features of SCA2 usually begin in the fourth decade of life. However, a wide range of clinical presentations have been reported (from the first to the eighthieth decade of life). The infantile and juvenile onset of SCA2 symptoms are associated with larger CAG repeat size.

Comentários finais

Here, we present the unusual case of a patient with 66 CAG repeat expansion in ATXN2 gene and beginning of symptoms at the age of three years old.

Referências

(1) Antenora A, Rinaldi C, Roca A, Pane C, Lieto M, Saccà F, Peluso S, De Michele G, Filla A. The Multiple Faces of Spinocerebellar Ataxia type 2. Ann Clin Transl Neurol. 2017 Aug 10;4(9):687-695. doi: 10.1002/acn3.437. PMID: 28904990; PMCID: PMC5590519.
(2) Pulst SM. Spinocerebellar Ataxia Type 2. 1998 Oct 23 [Updated 2019 Feb 14]. In: Adam MP, Feldman J, Mirzaa GM, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2024. Available from: https://www.ncbi.nlm.nih.gov/books/NBK1275/
(3) Scoles DR, Pulst SM. Spinocerebellar Ataxia Type 2. Adv Exp Med Biol. 2018;1049:175-195. doi: 10.1007/978-3-319-71779-1_8. PMID: 29427103.

Palavras Chave

SCA2; Spinocerebellar Ataxia type 2; ATXN2