[Genetic analysis of a Chinese pedigree with an allele dropout at the HLA-B locus].

OBJECTIVE: To delineate a deletional mutation of the HLA-B gene in a Chinese pedigree. METHODS: A female patient with acute myeloid leukemia who had visited Liuzhou People's Hospital in April 2022 was selected as the study subject. Routine human leukocyte antigen (HLA) was determined by using PCR-sequence specific oligonucleotide polymorphism (PCR-SSOP) and PCR-sequence-based typing (PCR-SBT) methods. Next generation sequencing (NGS) was used to validate the candidate variant in the HLA-B gene. RESULTS: The PCR-SBT and SSOP results for the HLA-B locus were inconsistent for the patient and her daughter. The SSOP results of the two individuals were HLA-B*35:01, 40:02 and HLA-B*35:01, 40:01, respectively. However, the PCR-SBT results has indicated a mismatch with the nearest HLA-B*35:01 at exon 4. NGS results showed that the HLA-B*35:01 had a 9 bp deletion in the intron 5. The patient's husband was HLA-B*40:01, 58:01, which was normal. CONCLUSION: The variant in intron 5 of the HLA-B gene in this pedigree has mapped to a primer-binding region for the SBT reagent, which has affected the accuracy of PCR-SBT results.

[Analysis of genetic polymorphisms and a novel tri-allelic cloning sequence for the D13S317 locus among an ethnic Han Chinese population].

OBJECTIVE: To study the genetic polymorphisms of short-tandem repeats (STR) for the D13S317 locus among an ethnic Han Chinese population and verify a novel tri-allelic pattern identified for the locus. METHODS: A total of 378 paternity test cases from Guangdong Forensic Authentication Institute from October 17, 2017 to December 28, 2017 were selected as the study subjects. A GlobalFilerTM Express kit was used for the STR genotyping. Samples suspected for having a novel tri-allelic pattern were verified with a PowerPlex 21 kit. Potential variant of the primer-binding region and flanking sequences underlying the tri-allelic pattern was excluded by molecular cloning and sequencing. RESULTS: Six alleles were detected for the D13S317 locus, with the characteristic distribution frequencies being 8 (29.1%), 9 (13.1%), 10 (15.21%), 11 (24.21%), 12 (13.89%) and 13 (3.44%), respectively. In one of the families, the D13S317 locus of the proband was suspected to harbor a triband allele (8, 9, 10). A re-test has confirmed the result of initial test. Molecular cloning and sequencing analysis of the D13S317 locus in the proband and his daughter has failed to find allelic variants in the primer-binding region and flanking sequence, which has confirmed the novel tri-allelic pattern for the locus. CONCLUSION: A novel type 2 tri-allelic pattern (8, 9, 10) at the D13S317 locus has been identified among the ethnic Han Chinese population. The pattern has not been transmitted to the female offspring, and has been included in the international STRBase database for the first time.

Adaptive Admixture of HLA Class I Allotypes Enhanced Genetically Determined Strength of Natural Killer Cells in East Asians.

Human natural killer (NK) cells are essential for controlling infection, cancer, and fetal development. NK cell functions are modulated by interactions between polymorphic inhibitory killer cell immunoglobulin-like receptors (KIR) and polymorphic HLA-A, -B, and -C ligands expressed on tissue cells. All HLA-C alleles encode a KIR ligand and contribute to reproduction and immunity. In contrast, only some HLA-A and -B alleles encode KIR ligands and they focus on immunity. By high-resolution analysis of KIR and HLA-A, -B, and -C genes, we show that the Chinese Southern Han (CHS) are significantly enriched for interactions between inhibitory KIR and HLA-A and -B. This enrichment has had substantial input through population admixture with neighboring populations, who contributed HLA class I haplotypes expressing the KIR ligands B*46:01 and B*58:01, which subsequently rose to high frequency by natural selection. Consequently, over 80% of Southern Han HLA haplotypes encode more than one KIR ligand. Complementing the high number of KIR ligands, the CHS KIR locus combines a high frequency of genes expressing potent inhibitory KIR, with a low frequency of those expressing activating KIR. The Southern Han centromeric KIR region encodes strong, conserved, inhibitory HLA-C-specific receptors, and the telomeric region provides a high number and diversity of inhibitory HLA-A and -B-specific receptors. In all these characteristics, the CHS represent other East Asians, whose NK cell repertoires are thus enhanced in quantity, diversity, and effector strength, likely augmenting resistance to endemic viral infections.

[Establishment of sequence-based typing assay for KIR2DS4 gene and identification of a new allele KIR2DS4*016].

OBJECTIVE: To establish a reliable sequence-based typing method for KIR2DS4 and study its allele polymorphism in Chinese Han population. METHODS: Using PCR-SSP method to detect the positive or negative of KIR2DS4 gene in 222 random Chinese Han individuals, and then using the method of high fidelity and long-fragment PCR-SBT to amplify, sequence and genotype the exons 4 and 5 of KIR2DS4 positive individuals. RESULTS: We successfully amplified the fragment with 3.2 kb length contains exons 4 and 5 of KIR2DS4 and detected the KIR2DS4 allele frequency in Chinese Han population. 209 KIR2DS4 positive individuals were detected, and the positive rate is 94.1%. By sequence-based typing, we identified 12 genotypes and 7 alleles of KIR2DS4. The 6 known alleles and their detection frequency is as follows: KIR2DS4* 00101/011 (180, 81.1%), KIR2DS4* 010 (53, 23.9%), KIR2DS4* 004 (34, 15.3%), KIR2DS4* 003 (15 and 6.8%), KIR2DS4* 006 (2, 0.9%) and KIR2DS4* 015 (1, 0.5%). In this study, we found a new allele, KIR2DS4* 016, with the difference in exon 5 comparing its most similar allele KIR2DS4* 010. In the exon 5 of KIR2DS4* 010, there is a 22bp-deletion, while the exon 5 of KIR2DS4* 016 is normal. This is not a rare allele because it was detected 3 times in studied population and with the frequency of 1.4%. The sequence of the new allele sequence has been submitted to GenBank (accession no.: KC414890) and the IPD -KIR database (submission no.: IWS40001804), and was nominated by WHO nomenclature committee for HLA system. CONCLUSION: In this study, a sequence-based typing method for KIR2DS4 was established, and the polymorphism data of KIR2DS4 in Chinese Han population was enriched by studying the allele polymorphism and new allele.

[Polymorphisms of MICA gene and their linkage disequilibrium with HLA-B among ethnic Han Chinese from Shenzhen].

OBJECTIVE: To study the distribution of MICA alleles among ethnic Han Chinese blood donors from Shenzhen and their linkage disequilibrium with HLA-B gene. METHODS: For 143 randomly selected blood donors, the MICA and HLA-B alleles were determined with a PCR-sequence based typing (SBT) method. Allelic frequency, haplotypic diversity and linkage disequilibrium were analyzed with a Pypop software. RESULTS: Thirteen MICA and 35 HLA-B alleles were identified among the 143 blood donors, among which MICA*008:01 had the highest frequency (76/286), whilst MICA*008:01-HLA-B*40:01 and MICA*010-HLA-B*46:01 were the most common haplotypes. No novel allele was identified. CONCLUSION: The allele frequencies, haplotype diversities and linkage disequilibrium parameters under a high resolution can facilitate further studies and applications of the MICA and HLA-B genes.

[Association of genetic polymorphisms of KIR-HLA system with chronic myeloid leukemia among ethnic Hans from southern China].

OBJECTIVE: To explore the association of KIR-HLA gene polymorphism with chronic myeloid leukemia (CML) among ethnic Hans from southern China. METHODS: A total of 172 adult CML patients and 480 unrelated healthy controls were screened for the presence of KIR with sequence-specific primers-PCR (PCR-SSP) and sequence-based typing (SBT) of HLA-A, -B and -C loci. Polymorphisms of the KIR-HLA system were analyzed at 4 levels, and the frequencies of KIR framework genes and KIR profiles, classⅠHLA ligands, matched KIR+HLA pairs and KIR-HLA compound profile were compared between the two groups. P values were calculated using SPSS 13.0 software. RESULTS: For the CML group, the frequencies of HLA-C2 ligand, 2DL1+HLA-C2 pair and HLA-B Bw4-80I were significantly lower than those of the control group, suggesting a protective effect against CML (HLA-C2: OR=0.386, 95%CI:0.240-0.620, P<0.01; 2DL1+HLA-C2: OR=0.316, 95%CI:0.191-0.525, P<0.01; HLA-B Bw4-80I: OR=0.576, 95%CI:0.384-0.862, P<0.01). The frequencies of KIR2DL1 ligand (HLA-C2) and KIR3DL1 ligand (HLA-B Bw4-80I) in the CML group were significantly lower than that of the control group, suggesting that the HLA-C2 and HLA-B Bw4-80I expression is probably decreased in the CML patient group, which led to reduced inhibitory signal and enhanced activating signal of KIR2DL1+ and/or KIR3DL1+ NK cells. Notably, the frequency of KIR-HLA compound profiles ID2 (KIR AA1-HLA-C1/C1-Bw6/Bw6-A3/11) in CML patients significantly increased in the CML patient group compared with the control group, suggesting that the KIR-HLA compound profiles ID2 may be a risk factor for CML (OR=2.163, 95%CI 1.198-3.906, P<0.01). CONCLUSION: Above analysis has identified certain protective and risk factors for CML from the KIR-HLA system, which may provide a clue for the pathogenesis of leukemia and development of individualized immune therapy.

[Genetic polymorphisms of KIR2DS4 gene among ethnic Hans from southern China].

OBJECTIVE: To study genetic polymorphisms of the KIR2DS4 gene among ethnic Hans from southern China. METHODS: Genomic DNA was isolated from 306 unrelated individuals and amplified with KIR2DS4-specific PCR primers. KIR2DS4-positive samples were genotyped for the entire coding sequence by sequencing-based typing (SBT). Assignment of allelic genotypes was accomplished by using Assign 3.5 software. For samples with inconclusive SBT results, RT-PCR products covering the entire coding sequence of the KIR2DS4 gene were subjected to cloning and haplotype sequencing. RESULTS: Among all tested samples, 297 were demonstrated to have carried the KIR2DS4 framework gene. For KIR2DS4-positive samples subjected to SBT for the entire coding sequences, no background was observed with the obtained sequences. Three of the seven identified alleles were of novel types, which were officially named by the KIR subcommittee of the World Health Organization Nomenclature Committee for Factors of HLA System. The observed frequencies for the 7 alleles were KIR2DS4*00101 (78.8%), *003 (10.5%), *004 (16.0%), *010 (23.2%), *017 (0.3%), *00105 (0.3%) and *018 (0.7%), respectively. Allele KIR2DS4*007 was not found. The overall frequency for normal cell-surface expression KIR2DS4 alleles including 2DS4*00101, *017 and *00105 was 79.4%, and that for non cell-surface expression alleles including 2DS4*003, *004, *010 and *018 was 50.4%. The ratio between the two was 1.6:1. CONCLUSION: The present study has elucidated the allelic diversity of KIR2DS4 among ethnic Hans from southern China, which may provide valuable data for transplantation as well as studies on KIR-associated disease and evolution.

[Study of polymorphisms of HLA class â (-A, -B, -C) and class â ¡ (DRB1, DQA1, DQB1, DPA1, DPB1) genes among ethnic Hans from Southern China].

OBJECTIVE: To study the genetic polymorphisms of human leukocyte antigen (HLA)- A, B, C, DRB1, DQA1, DQB1, DPA1and DPB1among ethnic Hans from southern China. METHODS: 481 randomly selected individuals were genotyped using a polymerase chain reaction (PCR) sequence-based typing (SBT) method for the above genes. Their allele frequencies were determined by direct counting. RESULTS: In total, 28 HLA-A, 57 HLA-B, 28 HLA-C, 40 HLA-DRB1, 18 HLA-DQA1, 17 HLA-DQB1, 6 HLA-DPA1and 21 HLA-DPB1alleles were identified. Among these, common alleles (with allelic frequencies > 0.05) included A*1101, A*2402, A*0207, A*3303, A*0201, B*40:01, B*46:01, B*58:01, B*13:01, B*15:02, C*01:02, C*07:02, C*03:04, C*03:02, C*08:01, C*03:03, C*04:01, DRB1*09:01, DRB1*15:01, DRB1*12:02, DRB1*08:03, DRB1*03:01, DRB1*04:05, DRB1*11:01, DQA1*01:02, DQA1*03:02, DQA1*03:03, DQA1*06:01, DQA1*01:03, DQA1*05:05, DQA1*01:04, DQA1*03:01, DQA1*05:01, DQB1*03:01, DQB1*03:03, DQB1*06:01, DQB1*05:02, DQB1*03:02, DQB1*02:01, DQB1*03:02, DQB1*06:02, DPA1*02:02, DPA1*01:03, DPA1*02:01, DPB1*05:01, DPB1*02:01, DPB1*13:01, DPB1*04:01and DPB1*02:02.For each of the locus, the overall frequencies of common alleles were 75.57%, 52.81%, 78.28%, 62.16%, 86.70%, 77.23%, 95.32% and 81.59%, respectively. CONCLUSION: The allelic frequencies of the 8 selected HLA loci among ethnic Hans from southern China may served as a reference for anthropology, legal medicine, transplantation and disease association studies.

[Analysis of ambiguities in HLA sequencing-based typing and its solutions].

OBJECTIVE: To investigate the number and ratio of ambiguous allele combinations from human leukocyte antigen (HLA) confirmatory test by sequencing based typing for unrelated donor marrow transplantation, and to establish an efficient strategy for identifying such ambiguities. METHODS: A total of 650 donor-receipt samples were genotyped for 5 loci of the HLA gene using an Atria SBT commercial kit. Exons 2, 3 and 4 of HLA-A, -B and -C, exon 2 of HLA-DRB1 and exons 2 and 3 of HLA-DQB1 were tested by routine HLA genotyping. The ratio of usual ambiguous allele combination was calculated. The ambiguities were subjected to further confirmatory test by PCR-SSP or PCR-SBT retest at outside of the routine sequencing region. RESULTS: Among the 650 tested samples, the ratio of ambiguity at HLA-A, B, C, DRB1 and DQB1 were 76.31% (496/650), 91.08% (592/650), 97.69% (635/650), 88.62% (576/650) and 43.38% (141/650), respectively. A total of 36 ambiguous allele combinations inside the routine sequencing region and 22 ambiguous allele combinations outside of the routine sequencing region were discovered. After removing rare alleles based on the Chinese common and well documented (CWD) Allele Table (Version 1.01), 9 ambiguous CWD allele combinations inside the routine sequencing region, including 3 located in HLA-B, HLA-C and 1 located in other three HLA loci were found. Ten ambiguous CWD allele combinations outside of the routine sequencing region, including 4 located in HLA-C, -DRB1 and 1 in HLA-A, -B respectively were determined. All samples with ambiguous CWD allele combinations could be distinguished by high-resolution PCR-SSP commercial kits or PCR SBT retest at outside of the routine sequencing region. CONCLUSION: The common and well documented allele combinations in sequencing-based typing at five HLA loci have been analyzed. Our strategy may provide valuable information for more efficient, low cost and accurate method for high resolution genotyping of HLA genes.

[Association of HLA-DPA1 and -DPB1 polymorphisms with Posner-Schlossman syndrome among southern Chinese Han population].

OBJECTIVE: To assess the association of HLA-DPA1 and -DPB1 polymorphisms with Posner-Schlossman syndrome (PSS) in southern Chinese Han population. METHODS: A total of 100 randomly selected PSS patients of southern Chinese Han origin were served as the experimental group, while 128 unrelated healthy blood donors of the same origin were served as the control group. All samples were subjected to sequencing-based typing (SBT) for exon 2 of HLA-DPA1 and -DPB1 loci in both directions. HLA genotype was assigned using an Assign 3.5 HLA SBT software. The allele frequencies and haplotype frequencies of HLA-DPA1 and -DPB1 of the two groups were compared. x² test, P value and odds ratio (OR) value were calculated. RESULTS: Six HLA-DPA1 alleles in the experimental group and 4 HLA-DPA1 alleles in the healthy control group were identified. The allelic frequency for HLA-DPA1*02:01 in the experimental group was significantly lower than the control group (4.50% vs. 12.109%; x²=8.124, P=0.004). Sixteen HLA-DPB1 alleles were identified in both the experimental and control groups. The allelic frequencies for HLA-DPB1*14:01 and - DPB1*17:01 in the experimental group were significantly lower than those of the control group ( DPB1*14:01: 1.00% vs. 4.688%, x²=5.130, P=0.024; DPB1*17:01: 0% vs. 2.344%, x²=3.897, P=0.048). The DPA1-DPB1 haplotypes for the experimental and control groups were 23 and 25, respectively. The haplotype frequencies for both DPA1*02:01- DPB1*14:01 and DPA1*02:01- DPB1*17:01 were significantly lower than those of the control group. CONCLUSION: DPA1*02:01- DPB1*14:01 and DPA1*02:01- DPB1*17:01 haplotypes may provide considerable protection effect against PSS in the southern Chinese Han population.

[Sequence analysis of a novel allele HLA-C*01:78].

OBJECTIVE: To investigate the genetic basis for a novel allele HLA-C*01:78. METHODS: Genomic DNA was extracted from peripheral blood using a QIAGEN quick DNA extraction kit. The regions encompassing HLA-C from exon 1 to intron 3 and intron 3 to 3'UTR were amplified and cloned using a cloning sequencing kit in order to split the two alleles apart. Selected clones were sequenced to include exons 2 to 4. RESULTS: Sequencing results have indicated the HLA-C alleles of the proband to be a novel C*03:04 allele. The sequence has been submitted to GenBank (KF049216). BLAST analysis has confirmed the novel allele to have one nucleotide difference as C*01:03 at genomic nt316C>A (codon 82CGC>AGC) in exon 2, which has resulted in replacement of one amino acid (82R>S). CONCLUSION: The novel allele has been officially named as C*01:78 by the WHO Nomenclature Committee. The HLA allele type of the proband was therefore A*02:07, 24:02; B*40:01, 46:01; C*01:78, 03:04; DQB1*05:02, 05:02; DRB1*16:02, 16:02.

Two novel HLA class II alleles, HLA-DRB1*09:57 and HLA-DRB1*09:58 in Chinese individuals.

Compared with HLA-DRB1*09:01:02:05, the alleles HLA-DRB1*09:57 and HLA-DRB1*09:58 each show one nucleotide change, respectively.

[The Polymorphism Analysis of HLA Class II Alleles Based on Next-Generation Sequencing and Prevention Strategy for Allele Dropout].

OBJECTIVE: To investigate the accuracy of next-generation sequencing technology (NGS) in detecting the polymorphisms of HLA-DRB1, DQB1, DQA1, DRB3, DRB4, DRB5, DPA1 and DPB1 alleles in randomly-selected unrelated healthy individuals from Shenzhen Han population, investigate the potential reason for HLA-DRB1 allele dropout in routine NGS, and establish an internal quality control system. METHODS: NGS-based HLA class II genotyping was performed on 1 012 samples using the MiSeqDxTM platform. The suspected missed alleles indicated by the quality control software and HLA-DRB1 homozygotes were confirmed by PCR-SSOP or PCR-SBT methods. RESULTS: A total of 139 alleles were detected, including HLA-DRB1(45), DRB3(7), DRB4(5), DRB5(7), DQA1(17), DQB1(21), DPA1(10) and DPB1(27). HLA-DRB1*09:01(17.09%),15:01(10.72%); DRB3*02:02(25.99%),03:01(10.18%); DRB4*01:03(36.46%); DRB5*01:01(15.42%); DQA1*01:02(20.01%),03:02(17.19%); DQB1*03:01(19.47%),03:03(17.98%), 05:02(11.66%), 06:01(10.67%); DPA1*02:02(54.45%), 01:03(31.18%) and DPB1*05:01(39.13%), 02:01(16.90%) alleles were the most common alleles in Shenzhen Han population (frequencies >10%). There was no statistical difference between the gene frequencies of HLA-DRB1 and DQB1 loci in our study. The HLA Common and Well-Documented Alleles in China (CWD2.4) (χ2=12.68, P >0.05). 94 cases of HLA-DRB1 homozygous samples detected by NGS were retested by PCR-SSOP or SBT method, and one case of allele dropout at HLA-DRB1 locus was found. SBT method confirmed that the allele of DRB1*04:03 was missed. The laboratory internal quality control system was established. Two cases of new alleles were detected and named by WHO Nomenclature Committee for Factors of the HLA System. CONCLUSION: The HLA genotyping results based on NGS showed a significantly lower ambiguity rate. The HLA class II alleles exhibit genetic polymorphism in the Han population of unrelated healthy individuals in Shenzhen. The independent method based on NGS in clinical histocompatibility testing has limitations and requires internal quality control strategies to avoid allele-dropout events.

[A study of HLA-DPA1 and DPB1 matching status for unrelated donor-recipient pairs matched at allele level for HLA-A, -B, -C, -DRB1 and -DQB1 loci].

OBJECTIVE: To analyze the status of HLA-DPA1 and DPB1 matching for unrelated donor-recipient pairs matched at high-resolution allele level for HLA-A, B, C, DRB1 and DQB1 loci. METHODS: A total of 76 unrelated donor-recipient pairs matching at allele level for HLA-A, B, C, DRB1 and DQB1 loci were subjected to HLA-DPA1 and DPB1 sequence-based typing (SBT). HLA-DPA1and DPB1 matching status at high-resolution allelic level was also analyzed. RESULTS: The allelic identity ratio for single HLA-DPA1 and DPB1 were 17.1% and 9.2%, respectively. HLA-DPA1 and DPB1 allelic identity ratio were both very low. The majority of unrelated donor-recipient pairs (73.7%) had an incompatibility at 1 HLA-DPA1 allele, 9.2% of pairs had an incompatibility at 2 DPA1 alleles. As for the high-polymorphic HLA-DPB1 gene, 57.9% of studied donor-recipient pairs had an incompatibility at 1 HLA-DPB1 allele, almost 1/3 (32.9%) of them were completely incompatible. When HLA-DPA1 and DPB1 genes were analyzed together, the donor-recipient pairs matched at 2/4 was the most common (51.4%), 4/4 allelic complete matched pairs accounted for 5.6%, and 0/4 matched pairs accounted for 8.3%. CONCLUSION: Our results indicated that the ratio of HLA-DPA1 and DPB1 complete match in the unrelated donor-recipient pairs matching at allelic level for HLA-A, B, C, DRB1 and DQB1 loci were very low. The effect of HLA-DPA1 and DPB1 matching status on clinical unrelated stem cell transplantation still needs to be elucidated.

Characterization of a novel variant allele, HLA-B*56:04:05, identified in a Chinese Han individual.

The novel HLA-B *56:04:05 allele differs from its most closely related allele B*56:04:01:01 in exon 4.

The novel HLA-B*13:179 variant detected by next generation sequencing in a Chinese individual.

HLA-B*13:179 differs from HLA-B*13:99 by one nucleotide substitution at position 829(A>G) in exon 4.

[Establishment of a large-scale bi-directional sequencing and genotyping platform for MICA gene exons 2 to 4].

OBJECTIVE: To establish a stable and large-scale bi-directional sequencing platform for genotyping MICA gene exons 2 to 4, and to analyze single nucleotide polymorphisms(SNP) of the region. METHODS: Primers for particular alleles of MICA gene exons 2 to 5 were designed. Optimal conditions for PCR amplification and sequencing reaction were explored. A commercialized one-way sequencing kit for MICA allele was used as a parallel control. Four samples carrying a MICA *010 allele were subjected to cloning and haplotype sequencing. RESULTS: Results of MICA allele typing of 100 samples for a parallel control group were confirmed by the establish method. Twenty-two SNP in MICA gene exons 2 to 4 were detected in Chinese population. Two novel allelic sequences were accepted by GenBank and IMGT/HLA database and officially named as MICA*065 and MICA*066 by the WHO Nomenclature Committee. A novel SNP in MICA gene intron 3 was discovered, with allelic sequence submitted to GenBank and IMGT/HLA database. CONCLUSION: The bi-directional sequencing genotyping platform may be applied for large-scale study of MICA allelic polymorphisms, tissue typing, organ transplantation and disease research.

Characterization of a novel variant allele, HLA-C*03:587, identified in a Chinese Han individual.

The novel HLA-C*03:587 allele differs from the closest allele C*03:03:01:01 in exon 5.

Establishment of Rapid Detection Methods for rs76971248 Related to Leukemia.

Background: The HLA-E gene is a member of the HLA-I gene family. Its genetic polymorphism is regarded as associated with numerous diseases. Establishing a rapid and accurate detection method of disease-related SNP sites in HLA-E is particularly important. Methods: Blood samples from 226 healthy blood donors and 228 leukemia patients were collected, and DNA was extracted. Three typing methods based on PCR-sequence-based typing, TaqMan genotyping, and high-resolution melting curve were established to identify rs76971248 (G>T). The Chi-square test was used for statistical analysis by SPSS. Results: Three methods based on PCR-SBT, TaqMan genotyping, and HRM were all able to identify rs76971248. The software for analyzing the results of HLA-E sequencing was easy to use, and the results were accurate. The frequency of rs76971248 in different types of leukemia patients was significantly lower than that in healthy blood donors (p < 0.05). And the frequency of the G/G genotype in leukemia patients was significantly higher than that in healthy blood donors (p < 0.05). Conclusions: For the screening of known SNP sites in large-scale populations, among the three methods, the TaqMan genotyping method had the advantage of shortest time consumption, simplest operation, and greatest specificity, which was the most appropriate method for this experiment. The analysis software for HLA-E gene sequencing needed to be further optimized. rs76971248 had a protective effect against leukemia. And the G/G genotype was a risk factor for leukemia.

[Study on HLA nucleotide sequence matching in epitope positions among recipient-donor pairs for allogenic hematopoietic stem-cell transplantation].

OBJECTIVE: To analyze the human leukocyte antigens(HLA)-A, -B, -Cw, -DRB1 and DQB1 nucleotide sequences between patients waiting for allogenic hematopoietic stem-cell transplantation (HSCT) and donors in Chinese population, and to establish strategy for maximizing optimal donor selection. METHODS: HLA high-resolution typing in a total of 537 recipient-donor pairs was determined by sequence based typing (SBT) method. The nucleotide BLAST tool was used to compare the nucleotide sequences among recipient-donor pairs. RESULTS: Only 16.20% (88/537) of recipient-donor pairs were found to fully match for nucleotide sequences of all HLA-A,-B,-Cw, -DRB1 and -DQB1 loci. Mismatch rate in single locus were 8.38% in HLA-A, 0.74% in HLA-B, 12.29% in HLA-C, 2.42% in HLA-DRB1, and 2.79% in HLA-DQB1, respectively. Mismatch rate in two or multiple HLA loci was 42.65%. Nonpermissive allele mismatch combinations (A 02:01-A 02:06, A 02:06-A 02:07, Cw 03:04-Cw 15:02, Cw 03:03-Cw 04:01, Cw 03:04-Cw 14:02, Cw 03:03-Cw 08:01, DRB1 04:03:01-DRB1 04:05) were detected in single mismatch HLA locus of recipient-donor pairs, mismatches of B 07:05:01-B 07:06, Cw 07:01:01-Cw 07:06 combinations outside of epitope positions were detected in two recipient-donor pairs. CONCLUSION: Our data suggested that attention should be paid in comparing nucleotide sequences between recipient and donor, and in distinguishing nucleotide sequence mismatches within and outside of the epitope positions. These results could serve as guidelines for donor selection.