OBJECTIVETo analyze genetic mutations and explore its molecular pathogenesis for an hereditary protein C (PC) deficiency pedigree.

METHODSThe 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.

RESULTSPlasma 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.

CONCLUSIONThe 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.

Humans ; Mutation ; Pedigree ; Protein C ; genetics ; Protein C Deficiency ; genetics

BACKGROUNDWe identified the gene mutations in two Chinese pedigree of type I hereditary protein C deficiency and type I hereditary antithrombin deficiency.

METHODSThe plasma level of protein C activity (PC:A), protein C antigen (PC:Ag), protein S activity, antithrombin activity (AT:A) and antithrombin antigen (AT:Ag) of propositi and two family members were detected using ELISA and chromogenic assay, respectively. All exons and intron-exon boundaries of protein C gene and antithrombin gene were analyzed by direct sequencing of the corresponding amplified PCR products in DNA from the propositus.

RESULTSThe plasma PC:A and PC:Ag of propositus 1 was 26% and 1.43 mg/dl, respectively. The PC:Ag and PC:A of his father were normal. The decreased PC:A level was seen in his mother and 4 of his maternal pedigree. PS:A and AT:A were all normal in pedigree 1 members. A C5498T heterozygous mutation in exon 3 of protein C gene, resulting in the substitution of Arg for Trp at the 15th amino acid, was identified in propositus 1 and 8 of his relatives. The plasma AT:A and AT:Ag of propositus 2 was 48.6% and 10.4 mg/dl, respectively. The reduced AT:A and AT:Ag levels were found in his father and 5 of paternal pedigree. PC:A, PC:Ag and PS:A were all in normal range. A heterozygous 13387-9G deletion in exon 6 of antithrombin gene was identified in propositus 2. This mutation introduced a frameshift and a premature stop at codon 426 and existed in 6 members of pedigree 2.

CONCLUSIONThe C5498T heterozygous mutation in exon 3 of protein C gene, first reported in China, leads to type I hereditary protein C deficiency. The 13387-9G deletion, a novel mutation, can cause antithrombin deficiency and thrombosis.

Adolescent ; Child ; Female ; Fibrin ; deficiency ; Gene Deletion ; Humans ; Male ; Pedigree ; Protein C ; genetics ; Protein C Deficiency ; genetics

Objective: To analyze the clinical manifestations and molecular pathogenesis of 18 patients with inherited protein S (PS) deficiency. Methods: Eighteen patients with inherited PS deficiency who were admitted to the Institute of Hematology & Blood Diseases Hospital from June 2016 to February 2019 were analyzed: activity of protein C (PC) and antithrombin (AT) , PS activity were measured for phenotype diagnosis; high throughput sequencing (HTS) was used for screening of coagulation disease-related genes; Sanger sequencing was used to confirm candidate variants; Swiss-model was used for three-dimensional structure analysis. Results: The PS:C of 18 patients ranged from 12.5 to 48.2 U/dL. Among them, 16 cases developed deep vein thrombosis, including 2 cases each with mesenteric vein thrombosis and cerebral infarction, and 1 case each with pulmonary embolism and deep vein thrombosis during pregnancy. A total of 16 PROS1 gene mutations were detected, and 5 nonsense mutations (c.134_162del/p.Leu45*, c.847G>T/p.Glu283*, c.995_996delAT/p.Tyr332*, c.1359G> A/p.Trp453*, c.1474C>T/p.Gln492*) , 2 frameshift mutations (c.1460delG/p.Gla487Valfs*9 and c.1747_1750delAATC/p.Asn583Wfs*9) and 1 large fragment deletion (exon9 deletion) were reported for the first time. In addition, the PS:C of the deep vein thrombosis during pregnancy case was 55.2 U/dL carrying PROC gene c.565C>T/p.Arg189Trp mutation. Conclusion: The newly discovered gene mutations enriched the PROS1 gene mutation spectrum which associated with inherited PS deficiency.
Antithrombin III/genetics* ; Female ; Genetic Testing ; Humans ; Mutation ; Pregnancy ; Protein C/genetics* ; Protein S/genetics* ; Protein S Deficiency/genetics*

Objective: To investigate the molecular pathogenesis and clinical features of unrelated 12 patients with inherited coagulation protein C (PC) deficiency in Chinese population. Methods: The PC activity (PC:A) and PC antigen (PC:Ag) were detected by chromogenic substrate and enzyme linked immunosorbent assay, respectively. The nine exons and flanking sequences of the protein C (PROC) gene were amplified by polymerase chain reaction with direct sequencing, and the suspected mutations were validated by reverse sequencing (clone sequencing for deletion mutations) . Results: The PC:A of the 12 probands decreased significantly, ranging from 18% to 55%, and the PC:Ag of the 10 probands decreased significantly. Eleven mutations were found, out of which four mutations [c.383G>A (p.Gly128Asp) , c.997G>A (p.Ala291Thr) , c.1318C>T (p.Arg398Cys) , and c.532G>C (p.Leu278Pro) ] were discovered for the first time. Six mutations were in the serine protease domain, four mutations were located in epidermal growth factor (EGF) -like domains, and one mutation was located in activation peptide. There were two deletion mutations (p.Met364Trp fsX15 and p.Lys192del) , and the rest were missense mutations. Mutations p.Phe181Val and p.Arg189Trp were identified in three unrelated families. All mutations may be inherited, and consanguineous marriages were reported in two families. Among the probands, nine cases had venous thrombosis, two cases had poor pregnancy manifestations, and one case had purpura. Conclusion: Patients with PC deficiency caused by PROC gene defects are prone to venous thrombosis, especially when there are other thrombotic factors present at the same time.
Humans ; Mutation ; Mutation, Missense ; Pedigree ; Phenotype ; Protein C/genetics* ; Protein C Deficiency/genetics*

OBJECTIVE: To explore the molecular pathogenesis of a Chinese pedigree affected with inherited protein C (PC) deficiency. METHODS: The protein C activity (PC:A) and protein C antigen (PC:Ag) of the proband and his family members were determined by a chromogenic substrate method and enzyme-linked immunosorbent assay, respectively. The proband was subjected to whole exome sequencing. Candidate variants were verified by Sanger sequencing of other members of the pedigree. RESULTS: The PC:A and PC:Ag of proband were reduced to 15% and 11%, respectively. The above parameters of his parents and elder sister were also decreased to approximately 50% of reference values. Next generation sequencing has revealed that the proband has harbored a heterozygous c.572_574delAGA (p.Glu191_Lys192delinsGlu) variant in exon 7 and a missense c.752C>T (p.Ala251Val) variant in exon 8 of the PROC gene. His father was heterozygous for the c.572_574delAGA variant, while his mother and elder sister were heterozygous for the c.752C>T variant. According to the American College of Medical Genetics and Genomics Standards and Guidelines, the c.572_574delAGA (p.Glu191_Lys192 delinsGlu) variant was predicted to be likely pathogenic (PS1+PM4+PP3). c.752 C>T (p.Ala251Val) variant was also likely pathogenic (PS1+PM1+PP3). CONCLUSION The deletional variant of c.572_574delAGA (p.Glu191_Lys192delinsGlu) in exon 7 and missense variant c.752C>T (p.Ala251Val) in exon 8 of the PROC gene probably underlay the inherited protein C (PC) deficiency in this pedigree. Above finding has enriched the spectrum of PROC gene variants and provided a basis for genetic counseling for this pedigree.
Humans ; China ; Mutation ; Pedigree ; Protein C/genetics* ; Protein C Deficiency/genetics* ; Male ; Female

Reduced protein S activity is one of the high-risk factors for venous thromboembolism.Hereditary protein S deficiency is an autosomal dominant disorder caused by mutations in the PROS1 gene.We reported a female patient with a mutation of c.292 G>T in exon 3 of the PROS1 gene,which was identified by sequencing.The genealogical analysis revealed that the mutation probably originated from the patient's mother.After searching against the PROS1 gene mutation database and the relevant literature,we confirmed that this mutation was reported for the first time internationally.
Humans ; Female ; Protein S/genetics* ; Protein S Deficiency/genetics* ; Pedigree ; Mutation

A 15-day-old boy was admitted to the hospital due to repeated convulsions for 14 days. The main clinical manifestations were uncontrolled seizures, hypoergia, feeding difficulties, limb hypotonia, and bilateral hearing impairment. Clinical neurophysiology showed reduced brainstem auditory evoked potential on both sides and burst-suppression pattern on electroencephalogram. Measurement of very-long-chain fatty acids in serum showed that C26:0 was significantly increased. Genetic testing showed a pathogenic compound heterozygous mutation, c.101C>T(p.Ala34Val) and c.1448_1460del(p.Ala483Aspfs*37), in the
Genetic Testing ; Humans ; Infant, Newborn ; Male ; Muscle Hypotonia ; Mutation ; Peroxisomal Multifunctional Protein-2/genetics* ; Protein Deficiency/genetics*

OBJECTIVETo analyze genetic mutation and explore its molecular pathogenesis for an hereditary protein C (PC) deficient consanguineous pedigree.

METHODSThe pedigree included three generations and contained eight members. PC activity (PC:A), PC antigen (PC:Ag) and other coagulant parameters were detected for all family members. Protein C gene (PROC) include all the exons and intron exon boundaries were amplified by PCR for the proband, then analyzed by direct sequencing. Mutation sites were detected for the other family members.

RESULTSThe PC:A and PC:Ag in the proband plasma were 20% (normal range 70% -140%) and 13.2% (normal range 70%-130%). A homozygous missense mutation g.6128T>G in exon 7 resulting in Phe139Val was identified in the proband. The PC:A and PC:Ag in her younger brother were 31% and 18.90%, Phe139Val homozygous was also found. The left family members were heterozygous for Phe139Val.

CONCLUSIONPhe139Val homozygous missense mutation in exon 7 of PROC caused serious hereditary protein C deficiency. We speculated that homozygous mutation might be resulted from this consanguineous marriage.

Adult ; Aged ; Consanguinity ; Female ; Homozygote ; Humans ; Male ; Middle Aged ; Mutation ; Pedigree ; Protein C ; genetics ; Protein C Deficiency ; etiology ; genetics

OBJECTIVE: To explore the genetic etiology for a fetus with hydrocephalus and intraventricular hemorrhage. METHODS: Trio whole exome sequencing was carried out. Candidate variants were verified by Sanger sequencing of the fetus and its parents. RESULTS: The fetus was found to harbor c.818G>A (p.W273X) and c.833T>C (p.L278P) compound heterozygous variants of the PROC gene, which were respectively inherited from its mother and father. Based on the guidelines of the American College of Medical Genetics and Genomics (ACMG), both variants were predicted to be likely pathogenic (PVS1_Strong+PM2_Supporting+PP4; PM2_Supporting+PM3+PP1+PP3+PP4). CONCLUSION The fetus was diagnosed with Protein C deficiency due to the c.818G>A (p.W273X) and c.833T>C (p.L278P) compound heterozygous variants of the PROC gene. Above finding has enriched the spectrum of PROC gene variants and enabled genetic counseling and prenatal diagnosis for the family.
Female ; Pregnancy ; Humans ; Protein C Deficiency ; Fetus ; Genetic Counseling ; Genomics ; Hydrocephalus/genetics* ; Mutation

Objective: To investigate the clinical characteristics and gene mutation, and analyze the association between genotype and phenotype of hereditary protein S deficiency in a Chinese pedigree. Methods: Hereditary protein S deficiency was diagnosed in January 2016 in our hospital. A total of 26 family members were surveyed in this study. Blood samples and clinical data were collected from them, and mutations were identified by Sanger sequencing. Pathogenicity of gene mutations was predicted by protein function prediction software including SIFT, PolyPhen_2, nsSNPAnalyzer and MutPred2. Swiss Model (https://swissmodel.expasy.org/) was used to perform homology modeling of the tertiary structure of the protein S wild-type and mutant-type, and observe the impact of gene mutation on the tertiary structure of the protein. Results: Four out of 26 family members of 4 generations were clinically diagnosed with hereditary protein S deficiency. The proband presented with recurrent pulmonary embolism and venous thromboembolism of the lower extremities, and her uncle and mother had a history of venous thromboembolism. Sequencing revealed a mutation in the c.200A>C gene in the second exon of the PROS1 gene of proband and part of her families (Ⅱ2, Ⅱ6, Ⅲ4, Ⅳ2). The prediction results of this gene mutation performed by SIFT, PolyPhen_2, nsSNPAnalyzer, MutPred2 were all harmful. The results of Swiss-Model homology modeling showed that the 67th amino acid was mutated from glutamic acid to alanine because of this gene mutation. Conclusion: A gene mutation cDNA (c. 200A>T) is identified in a Chinese pedigree with hereditary protein S deficiency. This gene mutation may reduce protein S activity, which may cause recurrent pulmonary embolism and venous thromboembolism of the patients.
Asians/genetics* ; Exons ; Female ; Humans ; Pedigree ; Protein S Deficiency ; Surveys and Questionnaires