Characterization of red blood cell parameters in southeast Asian ovalocytosis (SAO) and non-southeast Asian ovalocytosis (NON-SAO) with or without thalassaemia/haemoglobinopathies

SAO and thalassaemia/haemoglobinopathy traits are phenotypically mild. Coinheritance of these diseases may produce severe hemolysis and ineffective erythropoiesis. This study aims to identify the haematological differences and association between SAO and non-SAO groups with and without thalassaemia/haemoglobinopathy. Methods: A cross- sectional comparative study was performed on 424 subjects investigated for thalassaemia/haemoglobinopathies. 212 SAO subjects were selected based on classical SAO morphology from peripheral blood film (PBF). An equal 212 non-SAO subjects were selected by the absence of SAO morphology. The demographic data, complete blood count, haemoglobin analysis, and molecular result testing were reviewed. Data analysis was performed by Chi-square test, student’s t-test, and one-way ANOVA. P-value < 0.05 was considered significant. Results: SAO group had a significantly lower RBC count and higher MCH, MCHC, and RDW as compared to the non-SAO group (4.89 x1012/L vs 5.31 x1012/L, 24.4-pg vs 23.2 pg, 33.8 g/dL vs 31.8 g/dL, 17.9% vs 15.6%). SAO and thalassaemia/ haemoglobinopathy coinheritance demonstrated significantly higher RBC count and lower MCV and MCH as compared to SAO without the coinheritance (5.03 x1012/L vs 4.17 x1012/L, 70.4 fL vs 81.1 fL, 23.8 pg vs 28.1 pg). Hb comparison among SAO and thalassaemia/haemoglobinopathy coinheritance revealed non-significant differences except for SAO/β+ demonstrated a notable Hb, MCV, and MCH reduction, and RDW increment.