"If genetic studies confirm the presence of a founder effect for [Parkinson's disease] PD in Afrikaners, this would imply that there is a large number of individuals from this ethnic group who may potentially be at risk of developing this debilitating condition," it said in a study recently published in the "SA Medical Journal".
Genealogical research on hereditary diseases was carried out and PD in Afrikaners was traced back to a specific founder couple.
"Given the evidence of founder effects for other disorders in the Afrikaner population, we sought to determine whether a founder effect for PD also occurs in this population," it said.
A founder effect results when a small subset of a large population establishes a new population.
"In the case of Afrikaners, the disorders that occur at an unusually high frequency may indicate that the original Dutch, French, and German colonists who settled in the Cape carried those disease-causing genes at high frequency," it said.
Study participants were recruited from the Movement Disorders Clinic at Tygerberg Hospital in Cape Town, and from various support group meetings of the Parkinson's Association of SA.
"After the genealogical trees of the first 12 families were constructed it emerged that there was a single ancestral couple common to these families.
"This couple married in South Africa in 1668. The husband was born in the Netherlands and... the wife was born in Germany in 1655. They had 12 children," it said.
"After this couple was identified in the first 12 families examined, links to the couple could also be established in an additional 28 families in which there was sufficient genealogical information to trace ancestry."
The study found that 40 Afrikaner PD subjects were descended from the founder couple, and that on average there were between three and four ancestral lines for each PD subject.