The clinical and genetic characteristics of spinocerebellar ataxia type 7 (SCA 7) in three Black South African families.
OBJECTIVE
Spinocerebellar ataxia type 7 is a rare autosomal dominant neurodegenerative disorder characterized by progressive cerebellar and retinal degeneration, described in various population groups in the literature. This is the first description from South Africa. The objective was to document the clinical and genetic characteristics of our patients and to determine concordance with other described cases.


METHODS
The index cases were identified clinically on the basis of the typically described features of progressive ataxia with visual failure due to progressive cerebellar and retinal/macular degeneration. Associated neurological disturbances were documented. Where possible, and available, family members were assessed and pedigrees were delineated. Molecular tests for SCA expansions were determined in the index cases.


RESULTS
Three pedigrees of SCA 7 were identified. The patients were all Black South Africans. The genetic and clinical characteristics are typical for SCA 7.


CONCLUSIONS
SCA 7 is a rare distinct neurodegenerative disorder characterized by trinucleotide expansion.
Modi
G
G
Department of Medicine, Chris Hani Baragwanath Hospital and the University of the Witwatersrand, Johannesburg, South Africa.
Modi
M
M
Martinus
I
I
Rodda
J
J
Saffer
D
D
D000328:Adult; D000368:Aged; D001284:Atrophy / Q000000981:diagnostic imaging / Q000473:pathology; D044383:Black People / Q000235:genetics; D001933:Brain Stem / Q000000981:diagnostic imaging / Q000473:pathology; D002531:Cerebellum / Q000000981:diagnostic imaging / Q000473:pathology; D002648:Child; D004252:DNA Mutational Analysis; D017931:DNA Primers / Q000235:genetics; D005260:Female; D005654:Fundus Oculi; D018392:Genomic Imprinting / Q000235:genetics; D006801:Humans; D008268:Macular Degeneration / Q000175:diagnosis; D008297:Male; D010375:Pedigree; D017354:Point Mutation / Q000235:genetics; D016133:Polymerase Chain Reaction / Q000379:methods; D013019:South Africa; D020754:Spinocerebellar Ataxias / Q000175:diagnosis* / Q000235:genetics*; D014057:Tomography, X-Ray Computed; D019680:Trinucleotide Repeat Expansion / Q000235:genetics
D017931:DNA Primers