Ma L, Liu Y C, Zhu S W, Hu W J, Chen X, Xue M, Zhen L, Wu M H, Liu Y, Sun J
Immunohematology Laboratory, Jiangsu Province Blood Center, Nanjing, China.
Transfus Med. 2015 Feb;25(1):38-41. doi: 10.1111/tme.12185. Epub 2015 Mar 23.
The aim of this study was to investigate the molecular mechanism of the JK-null phenotype in the Chinese population.
The Jk(a-b-) phenotype is vanishingly rare and the molecular basis differs between ethnic groups. The information regarding the molecular basis of JK-null alleles in the Chinese population is limited.
Three unrelated Jk(a-b-) phenotype donors were selected from 52 260 randomly blood samples through the urea lysis test and serological analysis. The JK gene-coding regions were amplified by the polymerase chain reaction and the products were sequenced directly.
Sequencing results revealed that one sample of JK() B alleles carried the well-known Polynesian Jk(a-b-) mutation IVS5-1g>a. Another null allele, also on the JK() B background, presented with two heterozygous missense mutation, including nt222C>A(Asn74Lys) in exon 5 and nt896G>A(Gly299Glu) in exon 9. The third null allele carried two heterozygous missense mutations, nt222C>A and a novel allele nt737T>G(Leu246Arg) in exon 8. The family investigation revealed that the proband was JK() A(737T>G)/JK() B(222C>A).
The Jk(a-b-) phenotype in the Chinese population shows several different molecular mechanisms. A novel missense mutation nt737T>G of JK gene was found as associated with Jk(a-b-) phenotype.
本研究旨在探讨中国人群中JK基因缺失表型的分子机制。
Jk(a-b-)表型极为罕见，且不同种族之间的分子基础存在差异。关于中国人群中JK基因缺失等位基因分子基础的信息有限。
通过尿素溶解试验和血清学分析，从52260份随机血样中筛选出3名无亲缘关系的Jk(a-b-)表型献血者。采用聚合酶链反应扩增JK基因编码区，并对产物进行直接测序。
测序结果显示，1份JK()B等位基因样本携带众所周知的波利尼西亚Jk(a-b-)突变IVS5-1g>a。另一个同样基于JK()B背景的缺失等位基因存在两个杂合错义突变，包括外显子5中的nt222C>A（Asn74Lys）和外显子9中的nt896G>A（Gly299Glu）。第三个缺失等位基因携带两个杂合错义突变，即外显子8中的nt222C>A和一个新的等位基因nt737T>G（Leu246Arg）。家系调查显示，先证者为JK()A(737T>G)/JK()B(222C>A)。
中国人群中的Jk(a-b-)表型存在多种不同的分子机制。发现JK基因一个新的错义突变nt737T>G与Jk(a-b-)表型相关。
