Genotypic and Phenotypic Expressions in Red Cell Membrane Disorders

(I)日本人红细胞膜疾病的基因分型和表型研究：在第二年(2001-2002年)，红细胞膜疾病的研究在该项目第一年(2000-2001年)之后进一步扩大。研究对象为家系31例，遗传性球形细胞增多症13个家系16例。遗传性椭圆形细胞增多症(HE)2个家系中的3例。2例两家系总蛋白4.2缺乏(P4.2)，2例遗传性一家系口腔红细胞增多症，另1例在调查中。(2)日本HS基因分析：发现带3(B3)基因突变12例，移码突变3例，剪接突变1例，错义突变8例，锚蛋白(Ank)基因CANK突变19例。D：9个移码突变，4个无义突变，6个剪接突变，3个蛋白4.2(P4.2)基因错义突变(ELB42)。除EPB3的两个突变外，其余突变均为日本人群所特有。(3)红细胞膜蛋白基因甲基化状态：mfmN。本研究选择了3个红细胞膜蛋白基因P49、FT：B3(EPB3)、P4.2CELB42和B-Spectrin(SFTB)。在SPTB中，许多CpG位点作为看家基因之一存在，并且绝对没有甲基化。在ELB42中，在已建立的红系细胞系CUT-7中，CpG位点在红系前体细胞中没有甲基化，尽管在成熟的红系细胞中它们是甲基化的。在EPB3中，尽管在其他位置有合理的CpG位点甲基化，但E和G位点基本上是低甲基化的。

(I)Genotypic and phenotypic studies on red cell membrane disorders in the Japanese population : In the second year (2001 - 2002), studies on red cell membrane disorders were further extended following the first year of this project (2000 - 2001). The subjects were 64 cases from 31 independent kindred ; 16 cases of 13 kindred in hereditary spherocytosis(HS). Three cases of two kindred in hereditary elliptocytosis (HE). Two cases of two kindred in total deficiency of protein 4.2(P4.2), two cases of one kindred of hereditary stomatocylosis, and other cases under investigation. Total number of cases studied has reached to 1078 cases of 636 kindred since 1974.(II)Gene analysis in Japanese HS : We identified 12.mutations of band 3(B3) gene (EPB3) ; three frameshift mutations one splicing mutation, and eight missense mutations, 19 mutations of ankyrin (Ank) gene CANK. D : nine frameshift mutations, four nonsense mutations, and six splicing mutations, and three missense mutations of protein 4.2 (P4.2) gene (ELB42). Except for two mutations in EPB3, all the mutations were specific for the Japanese population.(III)State of methylation of the red cell membrane protein genes : mfmn. P49, FT Three red cell membrane protein genes were selected for this study : B3(EPB3), P4.2CELB42), and B -spectrin (SFTB). In SPTB, many CpG sites were present as one of house-keeping genes and absolutely unmethylated. In ELB42, CpG sites were unmethylated in the erythroid precursors in the established cell line CUT-7), although they were methylated in mature erythroid cells. In EPB3, sites E and G were substantially hypomethylated in spite of reasonably methylated CpG sites at other locations.