Molecular epidemiological study ovalocytosis in Indonesia

东南亚卵胞增多症(SAO)是一种遗传性椭圆形红细胞增多症，导致僵硬的椭圆形红细胞抵抗疟疾寄生虫的入侵。最近发现SAO的分子基础是一种改变的红细胞带3蛋白的异质性存在，该蛋白在细胞质和膜结构域之间的边界缺少9个氨基酸。为了弄清导致印尼卵细胞增多症的突变，我们分析了印尼龙目岛遗传性卵细胞增多症患者的红细胞带3蛋白基因。印尼患者被诊断为卵细胞增多症，因为他的外周血涂片检查发现75%的红细胞是卵细胞增多症。从血细胞中提取DNA样本，作为模板进行PCR扩增。为了确定带3基因的突变，175bp长的区域从NT扩散。扩增出带3蛋白的1098~1272个片段。从正常DNA中只观察到一条带。相反，从印度尼西亚卵胞增多症病例中获得了两条狭长的条带，即一条略小于对照，另一条与对照一起迁徙。对扩增产物进行了测序，结果表明，3号带基因的指标例具有异质性。正常大小的产物显示该序列与野生型完全匹配。较小的扩增产物有27个核苷酸缺失。这些发现证实了印尼卵母细胞也是异常带3蛋白的杂合子，该蛋白有9个氨基酸缺失。

Southeast Asian ovalocytosis (SAO) is a hereditaty from of elliptocytosis resulting in rigid, oval-shaped erythrocytes resistant to invasion by malaria parasites. The molecular basis for SAO was recently identified as a heterogeneous presence of an altered erythrocyte band 3 protein, which lacked nine amino acids at the boundary between cytoplasmic and membrane domains. In order to clarify the mutation responsible for Indonesian ovalocytosis, we analyzed the erythrocyte band 3 protein gene of hereditary ovalocytosis in Rombok, Indonesia.The Indonesian case was diagnosed to be ovalocytosis, because examination of his peripheral blood smear disclosed 75% of red blood cells were ovalocytic. DNA sample was extracted from blood cells and used as a template for PCR amplification. To determine a mutation in the band 3 gene, 175 bp long region spreading from nt. 1098 to 1272 of band 3 protein cDNA was amplified. From normal DNA only one band was visualized. In contrast, two narrowly separated bands were obtained from Indonesian ovalocytosis case i. e. ; the one slightly smaller than a control, the other comigrating with the control. These results showed that the index case is heterogeneous for the band 3 gene.The amplified products were sequenced. Normal size product disclosed the sequence completely matched with that of wild type. The smaller amplified product had a 27 nucleotides deletion. These findings confirmed that the Indonesian ovalocyte is also heterozygous for the abnormal band 3 protein that has nine amino acids deletion.