Compound Heterozygous Protein C Deficiency Caused by Two Mutations, Arg-178 to Gin and Cys-331 to Arg, Leading to Impaired Secretion of Mutant Protein C

SummaryThe protein C gene in a patient apparently homozygous for protein C deficiency was analyzed. Two different point mutations, each located in a different allele, were detected to reveal that the patient is a compound heterozygote. Mutation of Arg-178 (CGG) to Gin (CAG) [mutation I] was detected in exon VII, in the vicinity of activation peptide cleavage site by thrombin. Mutation of Cys-331 (TGC) to Arg (CGC) [mutation II] was found in exon IX, at one of the sites involved in disulfide bond formation in the catalytic domain of the heavy chain. The alteration of Cys-331 to Arg disables the formation of the disulfide bond and would alter the protein conformation. Transient expression assays using COS-7 cells transfected with protein C expression vectors containing each one of these two mutations suggested that each of the two mutations would lead to the protein C deficiency by an impairment of secretion of the respective mutant proteins.

Download Full-text

Protein C deficiency Hong Kong 1 and 2: hereditary protein C deficiency caused by two mutant alleles, a 5-nucleotide deletion and a missense mutation

Blood ◽

10.1182/blood.v80.1.126.126 ◽

1992 ◽

Vol 80 (1) ◽

pp. 126-133 ◽

Cited By ~ 11

Author(s):

Y Sugahara ◽

O Miura ◽

P Yuen ◽

N Aoki

Keyword(s):

Amino Acid ◽

Protein C ◽

Catalytic Domain ◽

Stop Codon ◽

Blot Hybridization ◽

Southern Blot Hybridization ◽

Expression Vectors ◽

Protein C Deficiency ◽

Mutant Proteins ◽

Southern Blot Hybridization Analysis

Abstract We characterized a mutant protein C gene from an individual with no detectable protein C antigen in blood plasma. Southern blot hybridization analysis with human protein C cDNA demonstrated neither gross deletion nor rearrangement of the gene. Sequencing all the exons and exon-intron boundaries of the gene except the 3′ noncoding region showed two mutant alleles. The one, derived from the mother, represents a deletion of 5 nucleotides (nt) (CCCGC) in the end of exon VI (mutation I), predicted to result in the generation of a new stop codon due to a reading frameshift and the premature termination of translation. The other, derived from the father, represents a point mutation (G to A) in exon IX (mutation II), resulting in an amino acid substitution, Gly-376(GGC) to Asp(GAC), in the catalytic domain of the protein. Allele-specific oligonucleotide probe hybridization confirmed the presence of the two mutations. Mutation I would result in a truncated polypeptide of 169 amino acid residues that lacks the heavy chain. Mutation II gives rise to an alteration of a highly conserved amino acid, Gly-376. These data indicate that this patient is a compound heterozygote of the two mutant alleles, each one inherited from each parent. Transient expression assays using COS-7 cells transfected with mutated protein C expression vectors suggested that each of the two mutations leads to the protein C deficiency by causing an impairment of secretion of the respective mutant proteins.

Download Full-text

Protein C deficiency Hong Kong 1 and 2: hereditary protein C deficiency caused by two mutant alleles, a 5-nucleotide deletion and a missense mutation

Blood ◽

10.1182/blood.v80.1.126.bloodjournal801126 ◽

1992 ◽

Vol 80 (1) ◽

pp. 126-133 ◽

Cited By ~ 1

Author(s):

Y Sugahara ◽

O Miura ◽

P Yuen ◽

N Aoki

Keyword(s):

Amino Acid ◽

Protein C ◽

Catalytic Domain ◽

Stop Codon ◽

Blot Hybridization ◽

Southern Blot Hybridization ◽

Expression Vectors ◽

Protein C Deficiency ◽

Mutant Proteins ◽

Southern Blot Hybridization Analysis

We characterized a mutant protein C gene from an individual with no detectable protein C antigen in blood plasma. Southern blot hybridization analysis with human protein C cDNA demonstrated neither gross deletion nor rearrangement of the gene. Sequencing all the exons and exon-intron boundaries of the gene except the 3′ noncoding region showed two mutant alleles. The one, derived from the mother, represents a deletion of 5 nucleotides (nt) (CCCGC) in the end of exon VI (mutation I), predicted to result in the generation of a new stop codon due to a reading frameshift and the premature termination of translation. The other, derived from the father, represents a point mutation (G to A) in exon IX (mutation II), resulting in an amino acid substitution, Gly-376(GGC) to Asp(GAC), in the catalytic domain of the protein. Allele-specific oligonucleotide probe hybridization confirmed the presence of the two mutations. Mutation I would result in a truncated polypeptide of 169 amino acid residues that lacks the heavy chain. Mutation II gives rise to an alteration of a highly conserved amino acid, Gly-376. These data indicate that this patient is a compound heterozygote of the two mutant alleles, each one inherited from each parent. Transient expression assays using COS-7 cells transfected with mutated protein C expression vectors suggested that each of the two mutations leads to the protein C deficiency by causing an impairment of secretion of the respective mutant proteins.

Download Full-text

Hereditary Thrombophilia Caused by Abnormality of the Anticoagulant Protein C Pathway: Prenatal Diagnosis of Compound Heterozygous Protein C Deficiency by Direct Detection of the Mutation Sites

Pulmonary Embolism ◽

10.1007/978-4-431-66893-0_2 ◽

1999 ◽

pp. 21-35

Author(s):

Masaru Ido ◽

Tatsuya Hayashi ◽

Junji Nishioka ◽

Koji Suzuki

Keyword(s):

Prenatal Diagnosis ◽

Protein C ◽

Direct Detection ◽

Compound Heterozygous ◽

Protein C Deficiency ◽

Hereditary Thrombophilia ◽

Heterozygous Protein C Deficiency

Download Full-text

Different impact of two mutations of a novel compound heterozygous protein C deficiency with late onset thrombosis

Genetics and Molecular Research ◽

10.4238/2014.april.16.5 ◽

2014 ◽

Vol 13 (2) ◽

pp. 2969-2977 ◽

Cited By ~ 2

Author(s):

L.-H. Yang ◽

M.-S. Wang ◽

F.-X. Zheng ◽

J. Li ◽

Y. Chen ◽

...

Keyword(s):

Protein C ◽

Late Onset ◽

Compound Heterozygous ◽

Protein C Deficiency ◽

Heterozygous Protein C Deficiency

Download Full-text

Compound heterozygous protein C deficiency in a family with venous thrombosis: Identification and in vitro study of p.Asp297His and p.Val420Leu mutations

Gene ◽

10.1016/j.gene.2015.03.002 ◽

2015 ◽

Vol 563 (1) ◽

pp. 35-40 ◽

Cited By ~ 7

Author(s):

Hui Liu ◽

Hua-Fang Wang ◽

Liang Tang ◽

Yan Yang ◽

Qing-Yun Wang ◽

...

Keyword(s):

Venous Thrombosis ◽

Protein C ◽

In Vitro Study ◽

Vitro Study ◽

Compound Heterozygous ◽

Protein C Deficiency ◽

Heterozygous Protein C Deficiency

Download Full-text

Case Report: Successful Long-Term Management of a Low-Birth Weight Preterm Infant With Compound Heterozygous Protein C Deficiency With Subcutaneous Protein C Concentrate Up to Adolescence

Frontiers in Pediatrics ◽

10.3389/fped.2021.591052 ◽

2021 ◽

Vol 9 ◽

Author(s):

Johannes Pöschl ◽

Wolfgang Behnisch ◽

Bernd Beedgen ◽

Navina Kuss

Keyword(s):

Cesarean Section ◽

Vitamin K ◽

Protein C ◽

Vitamin K Antagonists ◽

Compound Heterozygous ◽

Protein C Deficiency ◽

Protein C Concentrate ◽

Protein C Activity ◽

Heterozygous Protein C Deficiency

Homozygous/compound heterozygous forms of congenital protein C deficiency are often associated with severe antenatal and postnatal thrombotic or hemorrhagic complications. Protein C deficiency frequently leads to severe adverse outcomes like blindness and neurodevelopmental delay in children and may even lead to death. The most widely used long-term postnatal treatment consists of oral anticoagulation with vitamin K antagonists (e.g., warfarin), which is supplemented with protein C concentrate in acute phases. Subcutaneous infusions have been described in infants mostly from 2 months of age after severe postnatal thrombosis, but not in newborns or premature infants without thromboembolism. We report the first case of a compound heterozygous protein C-deficient preterm infant, born at 31+5 weeks of gestation to parents with heterozygous protein C deficiency (protein C activity 0.9% at birth). We focus on both prenatal and perinatal management including antithrombotic treatment during pregnancy, the cesarean section, and continuous postnatal intravenous and consecutive subcutaneous therapy with protein C concentrate followed by a change of therapy to direct oral anticoagulants (DOACs) (apixaban). We report successful home treatment with subcutaneous protein C concentrate substitution overnight (target protein C activity >25%) without complication up to 12.5 years of age. We propose that early planned cesarean section at 32 or preferably 34 weeks of gestation limits potential maternal side effects of anticoagulation with vitamin K antagonists and reduces fetal thromboembolic complications during late pregnancy. Intravenously administered protein C and early switch to subcutaneous infusions (reaching about 3 kg body weight) resulted in sufficient protein C activity and has guaranteed an excellent quality of life without any history of thrombosis for 13 years now. In older children with protein C deficiency, as in our case, DOACs could be a new therapeutic option.

Download Full-text