Spinocerebellar ataxia type 12 identified in two Italian families may mimic sporadic ataxia.
SCA12 is an autosomal dominant cerebellar ataxia characterized by onset in the fourth decade of life with action tremor of arms and head, mild ataxia, dysmetria, and hyperreflexia. The disease is caused by an expansion of >or=51 CAGs in the 5' region of the brain- specific phosphatase 2 regulatory subunit B-beta isoform (PPP2R2B) gene. SCA12 is very rare, except for a single ethnic group in India. We screened 159 Italian ataxic patients for SCA12 and identified two families that segregated an expanded allele of 57 to 58 CAGs, sharing a common haplotype. The age at onset, phenotype, and variability of symptoms were compatible with known cases. In one family, the disease was apparently sporadic due to possible incomplete penetrance and/or late age at onset. Our data indicate that SCA12 is also present in Italian patients, and its genetic testing should be applied to both sporadic and familial ataxias.
Brussino
Alessandro
A
Department of Genetics, Biology and Biochemistry, University of Torino, and S.C.D.U. Medical Genetics, A.O.U. San Giovanni Battista, Torino, Italy.
Graziano
Claudio
C
Giobbe
Dario
D
Ferrone
Marina
M
Dragone
Elisa
E
Arduino
Carlo
C
Lodi
Raffaele
R
Tonon
Caterina
C
Gabellini
Anna
A
Rinaldi
Rita
R
Miccoli
Sara
S
Grosso
Enrico
E
Bellati
Maria Cristina
MC
Orsi
Laura
L
Migone
Nicola
N
Brusco
Alfredo
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D001259:Ataxia / Q000503:physiopathology*; D005192:Family Health; D005260:Female; D006801:Humans; D007558:Italy; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000235:genetics*; D049268:Positron-Emission Tomography / Q000379:methods; D054648:Protein Phosphatase 2 / Q000235:genetics*; D011522:Protons; D012189:Retrospective Studies; D020754:Spinocerebellar Ataxias / Q000175:diagnosis* / Q000235:genetics; D019680:Trinucleotide Repeat Expansion / Q000235:genetics*; D055815:Young Adult
D009419:Nerve Tissue Proteins; D011522:Protons; C505936:PPP2R2B protein, human; D054648:Protein Phosphatase 2