title: Evidence for a common founder effect amongst South African and Zambian individuals with Spinocerebellar ataxia type 7.
abstract: Spinocerebellar ataxia type 7 (SCA7) is an inherited neurodegenerative disease caused by the expansion of a CAG repeat within the ataxin 7 gene, leading to a pathogenic polyglutamine tract within the ataxin 7 protein. SCA7 patients suffer from progressive cerebellar ataxia and macular degeneration. SCA7 is considered to be rare, although founder effects have been reported in South Africa, Scandinavia and Mexico. The South African SCA7-associated haplotype has not been investigated in any other populations, and there have been limited reports of SCA7 patients from other African countries. Here, we describe the first two ethnic Zambian families with confirmed SCA7. Haplotype analysis showed that the South African SCA7 haplotype alleles were significantly associated with the pathogenic expansion in affected Zambian individuals, providing strong evidence for a shared founder effect between South African and Zambian SCA7 patients.
authors.affiliation: Division of Human Genetics, Department of Clinical Laboratory Sciences, Institute of Infectious Disease and Molecular Medicine, Faculty of Heath Sciences, University of Cape Town, Cape Town, South Africa.
authors.forename: Danielle C
authors.initials: DC
authors.lastname: Smith
authors.affiliation: Department of Internal Medicine, School of Medicine, University of Zambia, Lusaka, Zambia.
authors.forename: Masharip
authors.initials: M
authors.lastname: Atadzhanov
authors.affiliation: Department of Internal Medicine, School of Medicine, University of Zambia, Lusaka, Zambia.
authors.forename: Mwila
authors.initials: M
authors.lastname: Mwaba
authors.affiliation: Division of Human Genetics, Department of Clinical Laboratory Sciences, Institute of Infectious Disease and Molecular Medicine, Faculty of Heath Sciences, University of Cape Town, Cape Town, South Africa. Electronic address: jacquie.greenberg@uct.ac.za.
authors.forename: Leslie Jacqueline
authors.initials: LJ
authors.lastname: Greenberg
mesh_terms: D044383:Black People / Q000208:ethnology / Q000235:genetics*; D005260:Female; D018703:Founder Effect; D006801:Humans; D008297:Male; D010375:Pedigree; D013019:South Africa / Q000208:ethnology; D020754:Spinocerebellar Ataxias / Q000175:diagnosis* / Q000208:ethnology / Q000235:genetics*; D015024:Zambia / Q000208:ethnology
keywords: Africa; Founder effect; Haplotype; Neurodegeneration; Polyglutamine; Spinocerebellar ataxia type 7