<i>CALR</i> and <i>MPL</i> frequencies were too low for meaningful association testing.<h4>Conclusion</h4><i>BCR::ABL1</i> was the most frequent abnormality, especially in younger age groups, whereas <i>JAK-2</i> p.V617F was linked to increasing age and female predominance.<h4>What this study adds</h4>MPN genetic testing in South Africa predominantly targeted male patients (ratio 1.4:1). The gene discussed is BCR; the disease is myeloproliferative neoplasm.