Southeast Asian ovalocytosis

Southeast Asian ovalocytosis is a form of hereditary elliptocytosis common in some communities in Malaysia and Papua New Guinea, as it confers some resistance to cerebral Falciparum Malaria.

Pathophysiology

Southeast Asian ovalocytosis

The primary defect in SAO differs significantly from other forms of elliptocytosis in that it is a defect in the gene coding for a protein that is not directly involved in the cytoskeleton scaffolding of the cell. Rather, the defect lies in a protein known as the band 3 protein, which lies in the cell membrane itself. The band 3 protein normally binds to another membrane-bound protein called ankyrin, but in SAO this bond is stronger than normal. Other abnormalities include tighter tethering of the band 3 protein to the cell membrane, increased tyrosine phosphorylation of the band 3 protein, reduced sulfate anion transport through the cell membrane, and more rapid ATP consumption. These (and probably other) consequences of the SAO mutations lead to the following erythrocyte abnormalities:

• A greater robustness of cells to a variety of external forces, including:
• Reduction in cellular sensitivity to osmotic pressures
• Reduction in fragility related to temperature change
• greater general......
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