ABSTRACT
No datasets are available on the basis of confirmed familial breast cancer patients and their respective mutation status for the South African Indian population. This dataset contains information collected in South Africa specifically for the South African Indian population (n = 223). The data involved a combined collection of laboratory confirmed genetic testing results, accompanied by immunohistochemical and anatomical pathology results. Various patient self-identified variables were also in measured. All the immunohistochemistry and anatomical pathology results were confirmed by a trained medical pathologist. Furthermore, mutation status and the detection of either benign polymorphisms or variants with an unknown clinical significance at the time of data collection were also reported. This dataset contains variables in a tabular format which includes the accompanying variables for each patient. All the patient-specific data were deidentified which allows for further exploration of the data with respect to the demography, immunohistochemistry and genetic material. This dataset has the potential to serve as the backbone for translational research and inquiries into this unique South African population.
ABSTRACT
Founder mutations in BRCA1 and BRCA2 have been reported in many different populations. We studied 105 Coloured and 16 Black Xhosa women residing in the Western Cape of South Africa diagnosed with breast cancer. We screened these patients using our standard panel of six previously reported SA Afrikaner and Ashkenazi Jewish BRCA1/2 mutations and identified only two Afrikaner mutations. Further screening by the protein truncation test (BRCA1 exon 11, and BRCA2 exons 10 and 11) revealed an additional four deleterious mutations (BRCA1 c.1504_ 1508del,p.Leu502AlafsX2, BRCA2 c.2826_2829del,p.Ile943LysfsX16, c.6447_6448dup,p.Lys2150IlefsX19 and c.5771_5774del,p.Ile1924Argfs X38). The latter, also known in Breast Cancer Information Core nomenclature as 5999del4, was identified in 4 of 105 (3.8%) Coloureds and 4 of 16 (25%) Xhosa women, which makes it a frequent founder mutation in the Western Cape Province. Although this mutation was previously reported to occur in the Netherlands, haplotype analysis indicated two distinct origins for the Dutch and South African mutations, excluding the possibility of a common Dutch ancestor and suggesting gene flow from the indigenous tribes such as the Xhosa to the Coloured population instead. Further studies to determine the carrier rate of this variant in the Xhosa and other SA populations are warranted.
