Molecular epidemiological study ovalocytosis in Indonesia

东南亚卵母细胞增多症（SAO）是一种遗传性的卵形细胞增多症，导致红细胞呈坚硬的卵形，可抵抗疟疾寄生虫的侵袭。最近发现，SAO的分子基础是红细胞3带蛋白的异质存在，该蛋白在细胞质和膜结构域之间的边界缺少9个氨基酸。为了明确印度尼西亚卵母细胞增多症的突变，我们分析了遗传性卵母细胞增多症的红细胞带3蛋白基因。印度尼西亚病例被诊断为卵圆细胞增多症，因为他的外周血涂片检查显示75%的红细胞是卵圆细胞。从血细胞中提取DNA样本，作为PCR扩增的模板。为了确定3带基因的突变，扩增了3带蛋白cDNA从nt. 1098到1272的175 bp长区域。从正常DNA中只能看到一条条带。相比之下，印度尼西亚卵母细胞增多症患者获得了两条狭窄的条带，即；一个比对照略小，另一个与对照平行。结果表明，该指标病例的3带基因具有异质性。扩增产物测序。正常大小产品显示的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，印度尼西亚卵母细胞也是杂合的异常带3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.