Spinocerebellar ataxia type 8 in Scotland: frequency, neurological, neuropsychological and neuropsychiatric findings.
OBJECTIVE
The objectives of this study were to: (i) establish whether the spinocerebellar ataxia type 8 (SCA 8) expansion is associated with ataxia in Scotland; (ii) test the hypothesis that SCA 8 is associated with neuropsychological impairment; and (iii) review neuroradiological findings in SCA 8.


METHODS
The methods included: (i) measurement of SCA 8 expansion frequencies in ataxic patients and healthy controls; (ii) comprehensive neuropsychological assessment of patients with SCA 8 and matched controls, neuropsychiatric interview; and (iii) comparison of patient and matched control magnetic resonance imaging (MRI) scans.


RESULTS
(i) 10/694 (1.4%) unrelated individuals with ataxia had combined CTA/CTG repeat expansions >100 compared to 1/1190 (0.08%) healthy controls (P < 0.0005); (ii) neuropsychological assessment revealed a dysexecutive syndrome among SCA 8 patients, not readily explained by motor or mood disturbance; neuropsychiatric symptoms occurred commonly; (iii) cerebellar atrophy was the only salient MRI abnormality in the patient group.


CONCLUSIONS
The SCA 8 expansion is associated with ataxia in Scotland. The disorder is associated with a dysexecutive syndrome.
Torrens
L
L
The Robert Fergusson Unit, Royal Edinburgh Hospital, Edinburgh, UK.
Burns
E
E
Stone
J
J
Graham
C
C
Wright
H
H
Summers
D
D
Sellar
R
R
Porteous
M
M
Warner
J
J
Zeman
A
A
D000328:Adult; D000368:Aged; D002531:Cerebellum / Q000473:pathology / Q000503:physiopathology; D003071:Cognition / Q000502:physiology; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D004252:DNA Mutational Analysis; D005260:Female; D005787:Gene Frequency; D005819:Genetic Markers; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005820:Genetic Testing; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis* / Q000209:etiology*; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000235:genetics*; D009483:Neuropsychological Tests; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; D012606:Scotland; D020754:Spinocerebellar Ataxias / Q000150:complications* / Q000235:genetics* / Q000523:psychology; D019680:Trinucleotide Repeat Expansion / Q000235:genetics
C415906:ATXN8OS gene product, human; D005819:Genetic Markers; D009419:Nerve Tissue Proteins; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated