Hemophilia A with reduced coagulation factor Ⅺ: a case report and literature review / 中国输血杂志

【Objective】 To investigate the possible molecular pathogenesis of a child with hemophilia A accompanied by coagulation factor Ⅺ reduction by testing coagulation-related indicators and genotyping in the child and his family. 【Methods】 Peripheral blood from the patient and his parents for detection of coagulation factors Ⅷ, Ⅸ, Ⅺ, Ⅻ, VWF∶Ag, lupus anticoagulants and F VIII, F XI inhibitors were collected. All exons and flanking sequences of the genes encoding FⅧ and FⅪ were sequenced and bioinformatically analyzed. 【Results】 The child had low FⅧ and FⅪ activity and no parental abnormalities were observed. The sequencing results showed that there was a c. 1834(exon12) C>T heterozygous mutation in the FⅧ gene and a c. 1817 (exon15) G>A heterozygous mutation in the FⅪ gene, which was de novo. Bioinformatics analysis shows that the FⅪ mutation changes the original protein structure and increases the number of carboxyl groups. 【Conclusion】 For patients with prolonged APTT, in addition to excluding factors that interfere with APTT testing, all coagulation factors related to APTT should be tested to clarify the diagnosis.

Characterization of the novel HLA-A*24:191 allele and analysis of its MHC molecular modeling structure / 中华医学遗传学杂志

OBJECTIVE@#To characterize a novel HLA allele, A*24:191, its DNA sequence, MHC modeling structure, and the possible influence of the amino-acid residue variations on the molecule.@*METHODS@#The HLA sequence was determined by Luminex PCR-SSO and PCR-SBT. Its MHC molecular structure and the possible effects of the amino-acid residue variations were modeled and analyzed with Phyre2, RCSB PDB and HistoCheck software.@*RESULTS@#The PCR-SBT revealed the novel A*24:191 differs from A*24:02 in exon 2 at position 256, 265, 270 with G>C, G>C, A>T. The MHC molecular structure prediction showed that, compared with A*24:02, the 62nd residue of A*24:191 changed from the acidic E to a neutral Q, both with the side chain extending outside the α helix pointing forward the groove, (Risler's score, R=2), the 65th changed from the smaller neutral G extending inside the helix to a basic R with a long-chain extending upward outside the helix (R=52), and the 66th changed from the basic K to a neutral N both with a long side chain extending inside the groove (R=31). The above residues are located on the α helix of the α 1 domain which constituting the side wall of the peptide-binding groove. The DSS Score=3.85. From the surface image of the molecule, it can be clearly seen that the variations of the properties, sizes and configurations of the residues caused significant changes in the shape of the surface structure of the α helix.@*CONCLUSION@#It suggested that the residue variations are likely to change the peptide binding properties as well as the TCR and antibody binding characteristics of the molecule.

Identification of a rare platelet-specific antigen HPA-10bw allele among ethnic Han Chinese population in Shandong / 中华医学遗传学杂志

OBJECTIVE@#To study the polymorphism of human platelet antigen (HPA) system 10 among ethnic Han Chinese from Shandong, China so as to supplement the data of platelet donor bank in the region.@*METHODS@#Peripheral blood samples of platelet donors from the region were genotyped for HPA-10 alleles by PCR-sequence specific primer (PCR-SSP) and direct sequencing.@*RESULTS@#Among 1401 donors, a rare heterozygote carrier of HPA-10w (a+b+) was identified, which gave an allelic frequency of approximately 0.035%.@*CONCLUSION@#The detection of rare HPA-10bw antigen allele among ethnic Han Chinese from Shandong is useful for the diagnosis and prevention of neonatal alloimmune thrombocytopenia and post-transfusion purpura in the region.