Case Report: β-thalassemia major on the East African coast

Abstract

Background: β-thalassemia is rare in sub-Saharan Africa and to our knowledge there has been no case of homozygous β-thalassemia major reported from this region. In a recent cohort study, we identified four β-thalassemia mutations among 83 heterozygous carriers in Kilifi, Kenya. One of the mutations identified was a rare β-globin gene initiation codon mutation (ATG➝ACG) (rs33941849). Here we present a patient with β-thalassemia major resulting from this mutation, only the second homozygous patient to have been reported. Methods: The female patient presented to Kilifi County Hospital aged two years with a one week left sided abdominal swelling. Clinical, hematological and genetic information were collected at admission and follow-up. Results: Admission bloods revealed marked anemia, with a hemoglobin (Hb) value of 6.6 g/dL and a low mean corpuscular volume of 64 fL. High performance liquid chromatography (HPLC) revealed the absence of HbA0 and elevated levels of HbF, suggesting a diagnosis of β-thalassemia major. Sequencing revealed that the child was homozygous for the rs33941849 initiation codon mutation. Conclusions: We hope that this study will create awareness regarding the presence of β-thalassemia as a potential public health problem in the East Africa region and will prompt the development of local guidelines regarding the diagnosis and management of this condition.

Keywords: East Africa; HbA2; rs33941849; sequencing; β-thalassemia major.

Figure 1.. HPLC chromatograms from study participants with normal hemoglobin A individual (HbAA), homozygous hemoglobin S (HbSS) and homozygous β-thalassemia patient at first admission (age 2.5 years) and at second admission (age 3.5 years).