Genotypic and Phenotypic Expressions in Red Cell Membrane Disorders

(1)日本人群中红细胞膜疾病的基因型和表型研究：在该项目第一年（2000 - 2001）的基础上，第二年（2001 - 2002）进一步扩展了红细胞膜疾病的研究。研究对象为来自31个独立亲属的64例；遗传性球形红细胞增多症（HS） 13个亲属16例。遗传性椭圆细胞增多症（HE）两家系3例。蛋白4.2（P4.2）总缺乏症两家系2例，遗传性口鼻病一家系2例，其他正在调查。自1974年以来，研究病例总数达到1078例，636例亲属。（二）日本HS基因分析：共鉴定出12株。3（B3）带基因（EPB3）突变；3个移码突变1个剪接突变，8个错义突变，锚蛋白（Ank）基因CANK突变19个。D：蛋白4.2 （P4.2）基因（ELB42）移码突变9个，无义突变4个，剪接突变6个，错义突变3个。除了EPB3的两个突变外，所有突变都是日本人群特有的。（三）红细胞膜蛋白基因mfmn的甲基化状态。本研究选择3个红细胞膜蛋白基因：B3（EPB3）、P4.2CELB42)和B -spectrin （SFTB）。在SPTB中，许多CpG位点作为管家基因之一存在，并且绝对未甲基化。在ELB42中，建立的细胞系CUT-7中红系前体的CpG位点未甲基化，尽管它们在成熟的红系细胞中被甲基化。在EPB3中，位点E和G基本上是低甲基化的，尽管其他位置的CpG位点有合理的甲基化。

(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.