Study on phenotypic screening and molecular genetics of rare blood type Jk(a-b-) in donors of Fujian province / 临床检验杂志

ABSTRACT

Objective To investigate the frequency of Jk(a-b-) phenotype of Kidd blood type system in blood donors of Fujian province and its genetic characteristics.Methods The Jk (a-b-) phenotype in the blood samples obtained from 180 626 donors were screened by using urea lysis assay and the suspected Jk(a-b-) pbenotype individuals were confirmed using conventional serological method.The genomic DNA covering the sequence from exon 1 to exon 11 of JK gene and respective flanking area(50-150 bp),as well as the promoter were amplified by polymerase chain reaction,and the products of PCR were directly sequenced.The genotypes of 7 SNPs of JK gene in the blood samples from 200 blood donors of Fujian province were detected by SNaPshot assay.Results Of 180 626 blood donors,15 cases with Jk(a-b-) phenotype were identified.The genomic analysis for the 15 cases revealed the four recessive JK-null alleles,i.e.,JK*B(IVS5-1G＞A),JK*B(896G＞A),JK*A(130G＞A,220A ＞G) and JK* B(130G ＞A,956C ＞ T) were observed with frequency of 66.67％,23.33％,6.67％ and 3.33％,respectively.SNaPshot results showed the frequency of JK * B (IVS5-1 G ＞ A) was 0.75 ％ and G130A was the common polymorphism.No A220G,C222T,C956T and G896A mutation was found in the 200 blood donors.Conclusion The frequency of Jk (a-b-) blood type in the donors of Fujian population was estimated about 0.008％.JK * B(IVS5-1G ＞ A) and JK * B(896G ＞ A) alleles may be the predominate circulating genes in Fujian population with Jk (a-b-) phenotype.Direct DNA sequencing revealed a novel allele leading to JK-null,SLC14A1 130A,220G.