Molecular background of weak D type 15 as the predominant weak D type found in Chinese population / 中国实验血液学杂志

This study was aimed to investigate the molecular genetic basis and serological phenotype of Rh weak D type 15 individuals. Samples were identified by serological tests and genotyped by sequence specific primer-PCR (SSP-PCR), and were sequenced to detect the changes of all ten RHD exons. The number of gene RHD was detected through SSP-PCR. The results showed that in tested individuals of weak D type confirmed by the IAT, 18 cases (56% in weak D) were weak D type 15. Rh factors found in 2 weak D type 15 individuals (11%) were C+c+E+e; Rh factors found in 2 weak D type 15 individuals (11%) were C+c+E-e+; others (78%) were c-c+E+e+. The results by serological tests were consistent with the results genotyped by PCR-SSP method. In all 18 samples, the sequencing result revealed a gene mutation 845G > A at the exon 6 of the RHD and the point mutation changed amino acid G282D of the RhD polypeptide. The zygosity test demonstrated that 2 out of 18 weak D type 15 individuals were RHD(+)/RHD(+) homozygous (two DCe/DcE), 16 cases were RHD(+)/RHD(-) heterozygous (two DCe/dce and fourteen DcE/dce). It is concluded that Weak D type 15 is predominant in weak D individuals of Chinese Han Nationality, and most of them are heterozygous with various RH haplotypes.

Analysis of genetic polymorphism in randomized donor's HPA 1-16 antigens and establishment of typed platelet donor data bank / 中国实验血液学杂志

To study the genetic polymorphism of HPA 1-16 platelet antigen alleles among unrelated volunteer donors and establish a typed platelet donor panel in Handan, typing was perfomed by polymerase chain reaction using sequence-specific primers (SSP-PCR); 148 random unrelated blood donors in Handan were genotyped for each of the HPA 1-16 antigen. The gene frequencies were analyzed and the genetype frequencies were determined by direct counting, and these data were compared with HPA distribution among various population by the chi-square test. The results indicated that HPA-1a, 2a, 4a-14a, 16a genes were found among the 16 HPAs in every sample tested. Monomorphic HPA-4a, 7a-14a, 16a were found in the samples. For HPA-1, 2, 5 and 6, a/a homozygosity was predominant with frequencies of 0.9595, 0.8108, 0.9865, 0.9797, respectively, and none of HPA b/b was found in the samples. HPA-1b, 2b, 5b, 6b were rarely found among subjects. HPA-15 had the greatest heterozygosity with a gene frequency of 0.2230, 0.5270, 0.2500 for HPA15a/15a, HPA15a/15b, HPA15b/15b, respectively. HPA-3 showed the second greatest heterozygosity with a gene frequency of 0.3851, 0.5135, 0.1014 for HPA3a/3a, HPA3a/3b, HPA3b/3b, respectively. HPA genotype frequencies showed a good fit to Hardy-Weinberg equilibrium. HPA1-5 gene frequencies for Chinese people in Handan were consistent with those of Chinese people in Shijiazhuang (P > 0.05). Among the HPA1-13, -15, the frequencies of HPA-1, -2, -6 for Chinese people in Handan differed appreciably from those for Chinese people in Taiwan (P < 0.05), others were similar to those of Chinese people in Taiwan. Among the HPA 1 - 8, a similarity was noted between Chinese people in Handan and Koreans (P > 0.05), except for HPA-3. Frequencies of HPA-1, -2, -5 significantly were differed from those in African Americans, as compared with HPA 1-5 (P < 0.05). Comparison of gene frequencies from HPA-1 and -5 showed significant differences between Chinese people in Handan and people in UK (P < 0.05). It is concluded that HPA-2, -3, -5, -15 of people in Western region of China have polymorphism, incompatible frequency of HPA antigen distribution is higher, which inevitably results in the increase of immunologic exposure, therefore attention must be paid to the importance of HPA-2, -3, -5, -15 in clinical disorders. This study for the first time completely analyses HPA1-16 gene frequencies in China, and provides data for establishing a typed platelet donor panel in Handan, China.