Pathogenic effect of an intermediate-size SCA-6 allele (CAG)(19) in a homozygous patient.
SCA6 is caused by CAG expansion in the alpha 1A voltage-dependent calcium channel subunit gene. The authors studied an Italian family in which one patient carried a fully expanded SCA6 allele with 26-CAG repeats, whereas the other affected family member was homozygous for an intermediate-size allele of 19-CAG repeats. Three family members, heterozygous for the intermediate allele, were clinically unaffected. The findings demonstrate a dose-dependent pathogenic effect of an intermediate CAG expansion in the SCA6 gene.
Mariotti
C
C
Division of Biochemistry and Genetics, National Neurological Institute-IRCCS Carlo Besta, Milan, Italy. mariotti@istituto-besta.it
Gellera
C
C
Grisoli
M
M
Mineri
R
R
Castucci
A
A
Di Donato
S
S
D000328:Adult; D015220:Calcium Channels / Q000235:genetics*; D002524:Cerebellar Ataxia / Q000235:genetics*; D005192:Family Health; D005260:Female; D006720:Homozygote; D006801:Humans; D008297:Male; D010375:Pedigree; D019680:Trinucleotide Repeat Expansion; D020864:Calcium Channels, N-Type
D015220:Calcium Channels; C105656:CACNA1A protein, human; D020864:Calcium Channels, N-Type