Haemoglobinopathies presenting with erythrocytosis is relatively rare. The clinicians might mistakenly diagnose such patients with other causes of erythrocytosis such as myeloproliferative neoplasm, etc instead of haemoglobinopathies. Here, we described two cases of haemoglobin variant, namely Haemoglobin Johnstown (Hb Johnstown) and Haemoglobin Bethesda (Hb Besthesda) that were detected following various futile investigations for persistent erythrocytosis. For both cases, the two main screening methods used were capillary electrophoresis (CE) and high performance liquid chromatography (HPLC). Approximately 30% of the high affinity haemoglobin (Hb) are not detected by electrophoresis method, however, in some cases, a variant Hb peak can be seen in chromatography method. Thus, a high index of suspicion of such diagnosis is utmost important as to not to miss the definitive diagnostic test by DNA analysis.
Haemoglobin S D-Punjab is a rare compound heterozygous haemoglobinopathy characterised by the presence of two β globin gene variants: Β6(GAG→GTG) and Β121(GAA→CAA). These patients' clinical and haematological features mimic haemoglobin S disease. We describe the first case of doubly heterozygous HbSD-Punjab from Malaysia managed with regular blood transfusion at the age of one. This case highlights the propensity for occurrence of rare phenotypes within our multi-ethnic population and emphasises the importance of accurate genotyping to avoid erroneous counselling, and to plan an effective patient management strategy before complication evolves.