Abstract: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-) phenotype individuals were confirmed using conventional serological method. The genomic DNA covering the sequence from exon 1 to exon 11 of K gene and respective flanking area(50150 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(IVS5-1G>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.