[A Family with Congenital Dysfibrinogenemia and Blood Transfusion].

OBJECTIVE: To investigate a family with congenital dysfibrinogenemia, and analyze the risk of hemorrhage and thrombosis and blood transfusion strategies. METHODS: Prothrombin time (PT), activated partial thromboplastin time (APTT) and thrombin time (TT) of the proband and her family members were detected by automatic coagulometer, fibrinogen (Fg) activity and antigen were detected by Clauss method and PT algorithm respectively. Meanwhile, thromboelastometry was analyzed for proband and her family members. Then, peripheral blood samples of the proband and her family members were collected, and all exons of FGA, FGB and FGG and their flanks were amplified by PCR and sequenced to search for gene mutations. RESULTS: The proband had normal APTT and PT, slightly prolonged TT, reduced level of Fg activity (Clauss method). The Fg of the proband's aunt, son and daughter all decreased to varying degrees. The results of thromboelastogram indicated that Fg function of the proband and her family members (except her son) was basically normal. Gene analysis showed that there were 6233 G/A (p.AαArg35His) heterozygous mutations in exon 2 of FGA gene in the proband, her children and aunt. In addition, 2 polymorphic loci were found in the family, they were FGA gene g.9308A/G (p.AαThr331Ala) and FGB gene g.12628G/A (p.BßArg478Iys) polymorphism, respectively. The proband was injected with 10 units of cryoprecipitate 2 hours before delivery to prevent bleeding, and no obvious bleeding occurred during and after delivery. CONCLUSION: Heterozygous mutation of 6233G/A (p.AαArg35His) of FGA gene is the biogenetic basis of the disease in this family with congenital dysfibrinogenemia.

[Gene Sequencing Analyses of 10 ABO Ambiguous Blood Group Samples].

OBJECTIVE: Through analysis of ABO blood group gene typing technology, to assist in the identification of difficult clinical serological specimens. METHODS: A total of 10 forwardreverse typing ambiguous samples were collected from January 2021 to August 2021 in our hospital.ABO genotypes were analysed by gene sequencing. RESULTS: The genotypes of 10 ABO ambiguous blood group samples were A102/BW11, A102/BW12, O02/O02, A102/B303, A102/B101, BW11/O02, B101/O04, BW11/O01, BW11/O01, A101/O02, respectively. The genotype results of 6 cases was consistent with the serological phenotype, and the serological phenotype of 4 cases were different from the geno sequencing. CONCLUSION: ABO blood groups genotyping technology combined with serological typing can be used for accurate typing of ambiguous blood group, and better ensure the safety of blood transfusion.

[Polymorphism of HLA-A, -B, -C, -DRB1 and -DQB1 Allele and Haplotype Frequency at High Resolution in Guangxi Zhuang Population].

OBJECTIVE: To analyze the characteristics of allelic and haplotypic polymorphisms of human leukocyte antigens at HLA-A, -B, -C, DRB1 and DQB1 loci in Guangxi Zhuang population. METHODS: Polymerase chain reaction-sequence based typing (PCR-SBT) was used to detect. The five loci (HLA-A, -B, -C, -DRB1, -DQB1) in 350 unrelated Zhuang ethnic individual from Guangxi region. Allelic and haplotypic frequencies were calculated by using Arlequin software 3.5.2.2. Phylogeny tree were constructed by using MEGA software 6.0, and SPSS software was used for principal component analysis. RESULTS: Among the five loci in the population, only HLA-A and DRB1 loci were observed as departures from Hardy-Weinberg expectations. A total of 19 HLA-A, 42 HLA-B, 22 HLA-C, 25 HLA-DRB1 and 15 HLA-DQB1 alleles were found in 350 samples. The most highest frequent alleles were A*11: 01(28.57%), B*46: 01(14.00%), C*01: 02(18.43%), DRB1*16: 02 (15.71%）and DQB1*05: 02 (35.00%) . The most common five loci haplotype was A*33: 03-C*03: 02-B*58: 01-DRB1*03: 01-DQB1*02: 01（6.86%）. The phylogenetic tree analysis showed that Guangxi Zhuang population had a relative close genetic relationship with southern Han Chinese populations. CONCLUSION: This reaserch found that the HLA-A, B, C, DRB1 and DQB1 loci are highly polymorphic in Guangxi Zhuang population.

[Identification of A Novel HLA-B*13:92 Allele and Analysis of Its 3D Model Structure].

OBJECTIVE: To identify a novel human leukocyte antigen (HLA) allele HLA-B*13:92 and analyze 3D model of HLA molecule. METHODS: Polymerase chain reaction sequencing-based (PCR-SBT) was used in routine HLA typing, the B locus typing results of one sample was one base mismatch with B*13:01:01, B*58:01:01 at locus 189, The Group Specific Sequencing Products (GSSP) which target at B*13 and B*58 were used to confirm difference between the new allele and highest homologous allele, then the new allele was modeled by Swiss-model to its 3D structure. RESULTS: The sequencing results showed that the new allele with highest homologous allele B*13:01:01 was the difference in the second exon at position 189 C>A (codon 39 GAC>GAA), 39 Asp (D) was changed to Glu (E). The amino acid substitution at residue 39 of the HLA polypeptide was located in α-helices of antigenic peptide-biding region. CONCLUSION: This allele is a new HLA-B allele found in Chinese Guangxi Zhang population and has been designated as HLA-B*13:92 by the World Health Organization (WHO) HLA Nomenclature Committee.