The hereditary adult-onset ataxias in South Africa.
There is little data on the spectrum and frequencies of the autosomal dominant spinocerebellar ataxias (SCAs) from the African continent. We undertook a large prospective population-based study over a 10-year period in South Africa (SA). Affected persons were clinically evaluated, and the molecular analysis for the SCA1, 2, 3, 6 and 7 expansions was undertaken. Of the 54 SA families with dominant ataxia, SCA1 accounted for 40.7%, SCA2 for 13%, SCA3 for 3.7%, SCA6 for 1.9%, SCA7 for 22.2% and 18.5% were negative for all these mutations. The frequency of the SCA1 and SCA7 expansions in SA represents one of the highest frequencies for these expansions reported in any country. In this study, the SCA7 mutations have only been found in SA families of Black ethnic origin.
Bryer
Alan
A
Division of Neurology, Department of Medicine, Groote Schuur Hospital and University of Cape Town (UCT), Cape Town, South Africa. abryer@uctgshl.uct.ac.za
Krause
Amanda
A
Bill
Pierre
P
Davids
Virginia
V
Bryant
Daphne
D
Butler
James
J
Heckmann
Jeannine
J
Ramesar
Rajkumar
R
Greenberg
Jacquie
J
D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000067696:Ataxin-1; D000067719:Ataxin-7; D000067528:Ataxins; D044383:Black People / Q000235:genetics; D002648:Child; D002869:Chromosome Aberrations; D004252:DNA Mutational Analysis; D005260:Female; D005787:Gene Frequency / Q000235:genetics; D005820:Genetic Testing; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000172:deficiency* / Q000235:genetics; D009687:Nuclear Proteins / Q000172:deficiency* / Q000235:genetics; D010641:Phenotype; D011446:Prospective Studies; D013019:South Africa / Q000453:epidemiology; D020754:Spinocerebellar Ataxias / Q000453:epidemiology / Q000235:genetics*; D019680:Trinucleotide Repeat Expansion / Q000235:genetics*; D044465:White People / Q000235:genetics
C000593749:ATXN1 protein, human; C000593829:ATXN7 protein, human; D000067696:Ataxin-1; D000067719:Ataxin-7; D000067528:Ataxins; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins