Search

Objective: To analyze genetic mutations and explore its molecular pathogenesis for an hereditary protein C (PC) deficiency pedigree., Methods: The pedigree has included 15 individuals from 4 generations. Plasma levels of PC activity (PC:A), PC antigen (PC:Ag) and other coagulant parameters were determined for members of the family. The 9 exons and intron-exon boundaries of protein C gene (PROC) of the proband were amplified with PCR and analyzed with direct sequencing. Detected mutations were confirmed with reverse sequencing. Corresponding PCR fragments from the family members were also directly sequenced., Results: Plasma PC:A and PC:Ag for the proband was 26% and 18.60%, respectively, both being lower than normal references. Seven members from the pedigree also had lower PC:A, six had lower PC:Ag. A compound heterozygous missense mutation, including a T to G transition at position 6128 of exon 7, which results in Phe139Val, and a G to C transition at position 8478 in exon 9, which results in Asp255His, were identified in the proband. The paternal grandma, father and two aunts were heterozygous for g.6128 T to G, whilst the mother, the second uncle, sister and son were heterozygous for g.8478 G to C. There were lower PC:A in family members with g.8478 G to C., Conclusion: The proband had inherited two independent mutations of the PROC gene including g.6128 T to G in exon 7 and g.8478 G to C in exon 9 from her father and mother, respectively. The resulting compound heterozygous mutation has caused a serious hereditary protein C deficiency.

Objective: To investigate potential mutations and clinical features of 9 unrelated patients with inherited coagulation factor VII (FVII) deficiency., Methods: Clinical diagnosis was validated by assaying of coagulation parameters including prothrombin time, activated partial thromboplastin time, FVII activity and specific antigens. All exons, exon-intron boundaries, and 5' and 3' untranslated regions of F7 genes were amplified with PCR. Potential mutations were detected by direct sequencing of purified PCR products. Suspected mutations were confirmed by sequencing of the opposite strand., Results: All probands have featured prolonged prothrombin time, with FVII activity ranging between 2.0% to 6.0%. The titers of FVII antigen were significantly reduced in 7 probands. Eight mutations, including 6 missense mutations, 1 deletion and 1 insertion, were identified, among which 3 (Gln100Leu, Ser269Pro and g.11520_11521insT) were not described previously. Six mutations have located in the protease domain. All mutations were inherited, and consanguineous marriages were reported in 5 families. Mutations g.27_28delCT, Cys329Gly, Arg304Trp and His348Gln have been identified in unrelated families. There was a lack of correlation between the mutations and their clinical features. Two individuals with homozygous His348Gln mutations and 1 individual with homozygous Arg304Trp mutation were only mildly affected or asymptomatic. Two patients, who have respectively carried homozygous and heterozygous deletions of g.27_28delCT, were moderately affected and asymptomatic. In 4 patients carrying double heterozygous mutations, 1 (Ser269Pro and Cys329Gly) was asymptomatic, 2 (Arg304Trp and Cys329Gly, Arg277Cys and g.11520_11521insT, respectively) had a mild bleeding tendency, whilst 1 (Gln100Leu and His348Gln) has a moderate bleeding diathesis., Conclusion: There seem to be hotspots of F7 gene mutations in ethnic Han Chinese populations. And there is a lack of correlation between particular types of mutations and clinical phenotypes.

Objective: To analyze genetic mutation and explore its molecular pathogenesis for an hereditary coagulation factor XII(F XII) deficiency in a pedigree featuring consanguineous marriage., Methods: Activated partial thromboplastin time (APTT), F XII procoagulant activity (F XII:C), F XII antigen (F XII:Ag) and other coagulant parameters were assayed. For the proband and his family members, exons 1-4, introns including the splice junctions of the F XII gene were amplified with polymerase chain reaction (PCR). The PCR product was purified and sequenced. The mutations were confirmed by sequencing the complimentary strand., Results: The proband has featured prolonged APTT at 157.5 s (reference range, 27.0-41.0 s). The APTT of his son has increased slightly at 48.3 s. The remaining members of the family were in normal range. F XII activity and F XII antigen of the proband were significantly decreased (<1%). The F XII activity of his wife, daughter, son and mother was also dropped to about 51%, 21%, 21% and 50%, respectively, and so was the F XII antigen (42%, 32%, 37% and 48%, respectively). Homozygous missense mutation of G→A transition at position 8699 in exon 14 resulting in Gly542Ser was identified in the proband. His mother, son and daughter were heterozygous for Gly542Ser. In the promoter regions of F XII gene, the genotype of the proband and the other members was 46T/T., Conclusion: Homozygous missense mutation Gly542Ser was found in a pedigree of hereditary F XII deficiency. The homozygous missense mutation might have resulted from his parents by consanguineous marriage. Gly542Ser and 46T/T have contributed to the pathogenesis of the hereditary factor XII deficiency pedigree.