¹Division of Human Genetics, Faculty of Health Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa

Correspondence: Professor J Greenberg, Division of Human Genetics, IIDMM, Faculty of Health Sciences, University of Cape Town Medical School, Anzio Rd, Observatory, 7925, Cape Town, South Africa. Tel: +27 21 4066299; Fax: +27 21 4066826; E-mail: jacquie.greenberg@uct.ac.za

Received 15 August 2006; Revised 24 January 2007; Accepted 25 January 2007; Published online 28 February 2007.

Abstract

This study involved the detailed investigation of the region surrounding the huntingtin gene in families with a history of Huntington Disease (HD) in South Africa. The primary aim was to investigate the origins of the HD mutation in South Africa by constructing a single-nucleotide polymorphism (SNP) haplotype around the HD gene and to determine how many haplotypes there are in two different South African populations. Haplotypes were created by genotyping six SNPs in a total of 13 HD families – seven Caucasian and six Mixed Ancestry. Of the six Mixed Ancestry families, four shared a common SNP haplotype, which was observed in two Afrikaans-speaking Caucasian HD families thus indicating that a founder effect was present in the South African population. The genotyping of a recently identified highly polymorphic marker close to the HD disease-causing mutation further corroborated the SNP haplotype results. Computational analysis was used to analyze the extent of the common haplotype identified in the study cohort in additional South African HD individuals. The results strongly suggest that the common haplotype extends further into the South African Mixed Ancestry HD population and is predominant in the Mixed Ancestry HD families.