Vitamin K-Dependent Coagulation Factor Deficiency

Mendelian MONDO:0015722 Pathograph 22 Show in embeddings browser hereditary disease inherited blood coagulation disorder

Congenital vitamin K-dependent coagulation factors deficiency (VKCFD) is an extremely rare autosomal recessive bleeding disorder caused by biallelic loss-of-function variants in GGCX (gamma-glutamyl carboxylase; VKCFD1) or VKORC1 (vitamin K epoxide reductase complex subunit 1; VKCFD2). Both enzymes are required for gamma-carboxylation, the vitamin K-dependent post-translational modification that activates the procoagulant factors II, VII, IX and X and the natural anticoagulants protein C and protein S. Defective gamma-carboxylation yields functionally defective, undercarboxylated clotting factors and a combined coagulation factor deficiency that presents as a bleeding diathesis, frequently from the neonatal period. Because GGCX also carboxylates non-hemostatic vitamin K-dependent proteins (e.g., matrix Gla protein, Gla-rich protein, osteocalcin), VKCFD1 can additionally cause skeletal, connective-tissue, and cardiovascular features.

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1
Inheritance
5
Pathophys.
11
Phenotypes
22
Pathograph
2
Genes
4
Medical Actions
2
Subtypes
2
References
1
Deep Research
👪

Inheritance

1
Autosomal Recessive HP:0000007
Autosomal recessive inheritance
Show evidence (1 reference)
PMID:19141161 SUPPORT Other
"Biochemical and molecular studies identify two variants of this autosomal recessive disorder"
Establishes autosomal recessive inheritance for both VKCFD subtypes.
◆

Subtypes

2
VKCFD type 1 (GGCX deficiency) MONDO:0010187
GGCX hgnc:4247
VKCFD1 is caused by biallelic pathogenic variants in GGCX, encoding gamma-glutamyl carboxylase. In addition to the bleeding diathesis, GGCX deficiency can produce non-hemorrhagic features (e.g., skin laxity, skeletal dysmorphology such as nasal hypoplasia and stippled epiphyses, and cardiac or vascular calcification) because non-coagulation vitamin K-dependent proteins are also undercarboxylated.
Show evidence (1 reference)
PMID:9845520 SUPPORT Human Clinical
"A missense mutation in gamma-glutamyl carboxylase gene causes combined deficiency of all vitamin K-dependent blood coagulation factors."
The first reported GGCX mutation in VKCFD establishes GGCX as the causative gene for VKCFD1.
VKCFD type 2 (VKORC1 deficiency) MONDO:0011837
VKORC1 hgnc:23663
VKCFD2 is caused by biallelic pathogenic variants in VKORC1, encoding the catalytic subunit of vitamin K epoxide reductase, which regenerates reduced vitamin K (the hydroquinone cofactor) required for gamma-carboxylation. The same gene harbors gain-of-function variants causing warfarin resistance.
Show evidence (1 reference)
PMID:14765194 SUPPORT Human Clinical
"VKORC1 contains missense mutations in both human disorders and in a warfarin-resistant rat strain."
Rost et al. identified VKORC1 as the gene mutated in VKCFD2, distinguishing it from the GGCX-related VKCFD1.
⚙

Pathophysiology

5
Vitamin K epoxide reductase deficiency (VKCFD2)
In VKCFD2, biallelic VKORC1 missense variants impair the vitamin K epoxide reductase complex, which recycles vitamin K 2,3-epoxide back to the reduced vitamin K hydroquinone cofactor. Loss of VKOR activity depletes the reduced vitamin K pool needed to drive gamma-carboxylation, upstream of the carboxylase reaction itself.
hepatocyte CL:0000182
vitamin K recycling (vitamin K metabolic process) GO:0042373 ↓ DECREASED
Downstream
Defective gamma-carboxylation of vitamin K-dependent proteins Reduced vitamin K hydroquinone cannot be supplied to the carboxylase, blocking carboxylation downstream.
Show evidence (2 references)
PMID:14765194 SUPPORT Human Clinical
"This complex recycles vitamin K 2,3-epoxide to vitamin K hydroquinone, a cofactor that is essential for the post-translational gamma-carboxylation of several blood coagulation factors."
VKOR recycling of vitamin K is required to supply the cofactor for carboxylation; its loss in VKCFD2 starves the carboxylase of reduced vitamin K.
PMID:14765194 SUPPORT In Vitro
"Overexpression of wild-type VKORC1, but not VKORC1 carrying the VKCFD2 mutation, leads to a marked increase in VKOR activity, which is sensitive to warfarin inhibition."
Functional expression confirms the VKCFD2 VKORC1 variant abolishes VKOR enzymatic activity.
Gamma-glutamyl carboxylase deficiency (VKCFD1)
In VKCFD1, biallelic GGCX variants reduce the activity of gamma-glutamyl carboxylase, the endoplasmic reticulum enzyme that carboxylates glutamate residues of vitamin K-dependent proteins. Different GGCX variants differentially impair carboxylation of individual substrates, which accounts for the variable combination of hemorrhagic and non-hemorrhagic phenotypes.
hepatocyte CL:0000182
gamma-carboxylation (peptidyl-glutamic acid carboxylation) GO:0017187 ↓ DECREASED
Downstream
Defective gamma-carboxylation of vitamin K-dependent proteins Reduced carboxylase activity directly prevents gamma-carboxylation of its protein substrates.
Show evidence (2 references)
PMID:9845520 SUPPORT In Vitro
"The mutated carboxylase protein expressed in Drosophila cells was stable but demonstrated threefold reduced activity compared with WT carboxylase, confirming that the L394R mutation results in a defective carboxylase."
Functional expression demonstrates that the causative GGCX variant directly reduces carboxylase activity.
PMID:34816548 SUPPORT In Vitro
"we have analyzed 20 pathogenic GGCX variants on their ability to γ-carboxylate six non-hemostatic VKD proteins"
GGCX variants differentially affect carboxylation of distinct vitamin K-dependent substrates, the basis of phenotypic heterogeneity in VKCFD1.
Defective gamma-carboxylation of vitamin K-dependent proteins
Both enzymatic defects converge on impaired gamma-carboxylation, the post-translational addition of a carboxyl group to specific glutamate residues. Gamma-carboxyglutamate residues are required for the calcium- dependent membrane binding and biological activity of vitamin K-dependent proteins. GGCX carboxylates 15 different vitamin K-dependent proteins spanning coagulation, calcification, and cell signaling.
hepatocyte CL:0000182
peptidyl-glutamic acid carboxylation GO:0017187 ↓ DECREASED
Downstream
Undercarboxylated, functionally defective coagulation factors Coagulation factors II, VII, IX and X lack the Gla residues needed for procoagulant activity.
Undercarboxylation of non-hemostatic vitamin K-dependent proteins Matrix Gla protein, Gla-rich protein and osteocalcin are also undercarboxylated, driving non-hemorrhagic features in VKCFD1.
Show evidence (1 reference)
PMID:35054981 SUPPORT Other
"The GGCX enzyme catalyzes the γ-carboxylation of 15 different vitamin K dependent (VKD) proteins, which have function in blood coagulation, calcification, and cell signaling."
Establishes that gamma-carboxylation by GGCX activates a broad set of vitamin K-dependent proteins beyond coagulation.
Undercarboxylated, functionally defective coagulation factors
Undercarboxylated factors II, VII, IX and X (and the anticoagulants protein C and protein S) are secreted but cannot bind calcium and phospholipid membranes normally, producing a functional combined deficiency of vitamin K-dependent coagulation factors and impaired blood coagulation.
hepatocyte CL:0000182
blood coagulation GO:0007596 ⚠ ABNORMAL
Downstream
Bleeding diathesis Deficient procoagulant activity manifests clinically as a bleeding tendency.
Intracranial hemorrhage Severe coagulation-factor dysfunction can cause life-threatening intracranial bleeding.
Reduced prothrombin (factor II) Factor II is one of the vitamin K-dependent clotting factors with deficient activity.
Reduced factor VII activity Factor VII activity is reduced as part of the combined vitamin K-dependent factor deficiency.
Reduced factor IX activity Factor IX activity is reduced as part of the combined vitamin K-dependent factor deficiency.
Reduced factor X activity Factor X activity is reduced as part of the combined vitamin K-dependent factor deficiency.
Prolonged prothrombin time Reduced extrinsic/common-pathway vitamin K-dependent factors prolong the prothrombin time.
Prolonged partial thromboplastin time Reduced intrinsic/common-pathway vitamin K-dependent factors prolong the partial thromboplastin time.
Show evidence (1 reference)
PMID:19141161 SUPPORT Other
"A rare inherited form of defective gamma-carboxylation resulting in early onset of bleeding was first described by McMillan and Roberts in 1966 and subsequently has been termed 'vitamin K-dependent clotting factor deficiency' (VKCFD)."
Links defective gamma-carboxylation to the combined clotting factor deficiency and bleeding phenotype.
Undercarboxylation of non-hemostatic vitamin K-dependent proteins
In VKCFD1, reduced gamma-carboxylation of matrix Gla protein (MGP) and Gla-rich protein (GRP) impairs their function as inhibitors of ectopic calcification and modulators of connective tissue, producing skin laxity, skeletal dysmorphology, and cardiovascular calcification. The pattern depends on which substrates a given GGCX variant fails to carboxylate. MGP and GRP are produced extrahepatically by chondrocytes, vascular smooth muscle cells, and dermal fibroblasts, which are the sites of the non-hemostatic pathology.
chondrocyte CL:0000138 vascular smooth muscle cell CL:0000359 dermal fibroblast CL:0002620
peptidyl-glutamic acid carboxylation GO:0017187 ↓ DECREASED
Downstream
Cutis laxa / skin laxity Reduced GRP gamma-carboxylation is linked to the VKCFD1 skin-laxity phenotype.
Epiphyseal stippling (chondrodysplasia punctata) Impaired vitamin K-dependent mineralization biology contributes to epiphyseal stippling.
Nasal hypoplasia Mineralization and skeletal dysmorphology can include hypoplastic nasal bone/Binder phenotype.
Show evidence (2 references)
PMID:34816548 SUPPORT In Vitro
"We observed that GGCX variants causing markedly reduced γ-carboxylation of Gla rich protein (GRP) in vitro were reported in patients with skin laxity."
Directly links undercarboxylation of the non-hemostatic protein GRP to the skin-laxity phenotype of VKCFD1.
PMID:35054981 SUPPORT Other
"The major manifestation of non-hemorrhagic phenotypes in VKCFD1 patients are mineralization defects."
Establishes that the non-hemorrhagic VKCFD1 phenotypes are driven by mineralization defects from undercarboxylated MGP/GRP.
⬡

Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.
Pathograph: causal mechanism network for Vitamin K-Dependent Coagulation Factor Deficiency Interactive directed graph showing how pathophysiology mechanisms, phenotypes, genetic factors and variants, experimental models, environmental triggers, and treatments relate through causal and linked edges.
●

Phenotypes

11
Blood 2
Bleeding diathesis Abnormal bleeding HP:0001892
Show evidence (1 reference)
PMID:40541254 SUPPORT Human Clinical
"The condition presents with a spectrum of bleeding symptoms ranging from mild to severe, often beginning in the neonatal period."
Directly supports the combined-deficiency bleeding diathesis as the cardinal manifestation of VKCFD.
Prolonged partial thromboplastin time Prolonged partial thromboplastin time HP:0003645
Show evidence (1 reference)
ORPHA:98434 SUPPORT Other
"HP:0003645 | Prolonged partial thromboplastin time | Frequent (79-30%)"
Orphanet lists prolonged partial thromboplastin time as a frequent laboratory phenotype of hereditary VKCFD.
Integument 1
Cutis laxa / skin laxity Cutis laxa HP:0000973
Show evidence (1 reference)
PMID:34816548 SUPPORT Human Clinical
"In addition to bleedings, some VKCFD1 patients develop skin laxity and skeletal dysmorphologies."
Supports skin laxity as a recognized non-hemorrhagic feature of GGCX-related VKCFD1.
Other 8
Intracranial hemorrhage Intracranial hemorrhage HP:0002170
Show evidence (1 reference)
PMID:34558179 SUPPORT Human Clinical
"stippled epiphyses, and brain abnormalities suggestive of a brain hemorrhage."
A prenatally diagnosed GGCX-VKCFD fetus had brain abnormalities suggestive of hemorrhage, supporting intracranial bleeding risk.
Reduced prothrombin (factor II) Abnormality of prothrombin HP:0012200
Show evidence (1 reference)
PMID:19141161 SUPPORT Other
"Combined deficiency of vitamin K-dependent clotting factors II, VII, IX and X (and proteins C, S, and Z)"
Defines the combined deficiency of factor II among the affected vitamin K-dependent factors.
Reduced factor VII activity Reduced factor VII activity HP:0008169
Show evidence (1 reference)
PMID:19141161 SUPPORT Other
"Combined deficiency of vitamin K-dependent clotting factors II, VII, IX and X (and proteins C, S, and Z)"
Defines the combined deficiency of factor VII among the affected vitamin K-dependent factors.
Reduced factor IX activity Reduced factor IX activity HP:0011858
Show evidence (1 reference)
PMID:19141161 SUPPORT Other
"Combined deficiency of vitamin K-dependent clotting factors II, VII, IX and X (and proteins C, S, and Z)"
Defines the combined deficiency of factor IX among the affected vitamin K-dependent factors.
Reduced factor X activity Reduced factor X activity HP:0008321
Show evidence (1 reference)
PMID:19141161 SUPPORT Other
"Combined deficiency of vitamin K-dependent clotting factors II, VII, IX and X (and proteins C, S, and Z)"
Defines the combined deficiency of factor X among the affected vitamin K-dependent factors.
Prolonged prothrombin time Prolonged prothrombin time HP:0008151
Show evidence (1 reference)
ORPHA:98434 SUPPORT Other
"HP:0008151 | Prolonged prothrombin time | Frequent (79-30%)"
Orphanet lists prolonged prothrombin time as a frequent laboratory phenotype of hereditary VKCFD.
Epiphyseal stippling (chondrodysplasia punctata) Epiphyseal stippling HP:0010655
Show evidence (1 reference)
PMID:34558179 SUPPORT Human Clinical
"Pathological examination showed a Binder phenotype, hypoplastic distal phalanges, stippled epiphyses, and brain abnormalities suggestive of a brain hemorrhage."
A prenatally diagnosed GGCX-VKCFD fetus exhibited stippled epiphyses (chondrodysplasia punctata).
Nasal hypoplasia Aplasia/Hypoplasia of the nasal bone HP:0010940
Show evidence (1 reference)
PMID:34558179 SUPPORT Human Clinical
"a male fetus with a brachytelephalangic chondrodysplasia punctata (CDP), absence of nasal bone, growth restriction, and bilateral ventriculomegaly at 18 weeks of gestation."
Documents absent nasal bone (nasal hypoplasia / Binder phenotype) in a GGCX-VKCFD fetus.
🧬

Genetic Associations

2
GGCX pathogenic variants (VKCFD1) (Causative)
Gene: GGCX hgnc:4247 relationship_type: CAUSATIVE variant_origin: GERMLINE
Show evidence (1 reference)
PMID:19141161 SUPPORT Other
"VKCFD1, which is associated with point mutations in the gamma-glutamylcarboxylase gene (GGCX)"
Establishes GGCX point mutations as the genetic basis of VKCFD1.
VKORC1 pathogenic variants (VKCFD2) (Causative)
Gene: VKORC1 hgnc:23663 relationship_type: CAUSATIVE variant_origin: GERMLINE
Show evidence (1 reference)
PMID:14765194 SUPPORT Human Clinical
"Mutations in VKORC1 cause warfarin resistance and multiple coagulation factor deficiency type 2."
Identifies VKORC1 missense mutations as the cause of VKCFD2 (multiple coagulation factor deficiency type 2).
💊

Medical Actions

4
Vitamin K supplementation
Action: nutritional supplementation MAXO:0000106
Agent: vitamin K1 (phylloquinone) CHEBI:18067
High oral (or parenteral) doses of vitamin K are the primary treatment and prophylaxis, usually resulting in partial correction of the factor deficiency. Response depends on residual enzyme activity.
Mechanism Target:
RESTORES Defective gamma-carboxylation of vitamin K-dependent proteins — Supraphysiologic vitamin K can partially restore the reduced vitamin K cofactor pool and drive residual carboxylase activity.
Show evidence (1 reference)
PMID:19141161 SUPPORT Other
"Therapy includes high oral doses of vitamin K for prophylaxis, usually resulting in partial correction of factor deficiency"
Establishes high-dose vitamin K as the mainstay of VKCFD prophylaxis with partial response.
Fresh frozen plasma transfusion
Action: Fresh Frozen Plasma Transfusion NCIT:C116475
Transfusion of fresh frozen plasma is often required during surgery or in cases of severe bleeding to replace the deficient vitamin K-dependent factors.
Mechanism Target:
BYPASSES Undercarboxylated, functionally defective coagulation factors — FFP supplies functional vitamin K-dependent coagulation factors, bypassing the patient's defective endogenous factors.
Show evidence (1 reference)
PMID:40541254 SUPPORT Human Clinical
"with transfusions of fresh frozen plasma often required during surgery or in cases of severe bleeding."
Supports fresh frozen plasma transfusion for acute or perioperative bleeding in VKCFD.
Prothrombin complex concentrate
Action: Pharmacotherapy NCIT:C15986
Prothrombin complex concentrates (PCCs), which contain the vitamin K-dependent factors II, VII, IX and X, can be used episodically, including in combination with recombinant activated factor VII and vitamin K.
Mechanism Target:
BYPASSES Undercarboxylated, functionally defective coagulation factors — PCCs supply functional factors II, VII, IX and X, bypassing the patient's undercarboxylated endogenous factors.
Show evidence (1 reference)
PMID:40541254 SUPPORT Human Clinical
"alternative therapies such as prothrombin complex concentrates (PCCs) or a combination of recombinant activated factor VII and vitamin K may be considered."
Supports prothrombin complex concentrate as an alternative therapy for VKCFD bleeding.
Recombinant activated factor VII (rFVIIa)
Action: Pharmacotherapy NCIT:C15986
Agent: recombinant activated factor VII (eptacog alfa) NCIT:C81125
Recombinant activated factor VII (rFVIIa, eptacog alfa) can be considered for life-threatening or refractory bleeding, in combination with vitamin K, to bypass the deficient vitamin K-dependent coagulation factors.
Mechanism Target:
BYPASSES Undercarboxylated, functionally defective coagulation factors — rFVIIa promotes thrombin generation independently of the patient's undercarboxylated factors, bypassing the functional combined factor deficiency.
Show evidence (1 reference)
PMID:40541254 SUPPORT Human Clinical
"alternative therapies such as prothrombin complex concentrates (PCCs) or a combination of recombinant activated factor VII and vitamin K may be considered."
Supports recombinant activated factor VII as an alternative therapy for VKCFD bleeding.
{ }

Source YAML

click to show 
name: Vitamin K-Dependent Coagulation Factor Deficiency
creation_date: "2026-06-08T00:00:00Z"
description: >-
  Congenital vitamin K-dependent coagulation factors deficiency (VKCFD) is an
  extremely rare autosomal recessive bleeding disorder caused by biallelic
  loss-of-function variants in GGCX (gamma-glutamyl carboxylase; VKCFD1) or
  VKORC1 (vitamin K epoxide reductase complex subunit 1; VKCFD2). Both enzymes
  are required for gamma-carboxylation, the vitamin K-dependent post-translational
  modification that activates the procoagulant factors II, VII, IX and X and the
  natural anticoagulants protein C and protein S. Defective gamma-carboxylation
  yields functionally defective, undercarboxylated clotting factors and a
  combined coagulation factor deficiency that presents as a bleeding diathesis,
  frequently from the neonatal period. Because GGCX also carboxylates
  non-hemostatic vitamin K-dependent proteins (e.g., matrix Gla protein,
  Gla-rich protein, osteocalcin), VKCFD1 can additionally cause skeletal,
  connective-tissue, and cardiovascular features.
category: Mendelian
parents:
- hereditary disease
- inherited blood coagulation disorder
synonyms:
- VKCFD
- combined deficiency of vitamin K-dependent clotting factors
- vitamin K-dependent clotting factors, combined deficiency of
- multiple coagulation factor deficiency
inheritance:
- name: Autosomal Recessive
  inheritance_term:
    preferred_term: Autosomal recessive inheritance
    term:
      id: HP:0000007
      label: Autosomal recessive inheritance
  evidence:
  - reference: PMID:19141161
    reference_title: "Familial deficiency of vitamin K-dependent clotting factors."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      Biochemical and molecular studies identify two variants of this autosomal
      recessive disorder
    explanation: Establishes autosomal recessive inheritance for both VKCFD subtypes.
disease_term:
  preferred_term: congenital vitamin K-dependent coagulation factors deficiency
  term:
    id: MONDO:0015722
    label: congenital vitamin K-dependent coagulation factors deficiency
references:
- reference: PMID:40541254
  title: "Hereditary Combined Deficiency of the Vitamin K-Dependent Coagulation Factors."
- reference: PMID:19141161
  title: "Familial deficiency of vitamin K-dependent clotting factors."

has_subtypes:
- name: VKCFD1
  display_name: VKCFD type 1 (GGCX deficiency)
  subtype_term:
    preferred_term: vitamin K-dependent clotting factors, combined deficiency of, type 1
    term:
      id: MONDO:0010187
      label: vitamin K-dependent clotting factors, combined deficiency of, type 1
  description: >-
    VKCFD1 is caused by biallelic pathogenic variants in GGCX, encoding
    gamma-glutamyl carboxylase. In addition to the bleeding diathesis, GGCX
    deficiency can produce non-hemorrhagic features (e.g., skin laxity, skeletal
    dysmorphology such as nasal hypoplasia and stippled epiphyses, and cardiac
    or vascular calcification) because non-coagulation vitamin K-dependent
    proteins are also undercarboxylated.
  genes:
  - preferred_term: GGCX
    term:
      id: hgnc:4247
      label: GGCX
  evidence:
  - reference: PMID:9845520
    reference_title: "A missense mutation in gamma-glutamyl carboxylase gene causes combined deficiency of all vitamin K-dependent blood coagulation factors."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      A missense mutation in gamma-glutamyl carboxylase gene causes combined
      deficiency of all vitamin K-dependent blood coagulation factors.
    explanation: The first reported GGCX mutation in VKCFD establishes GGCX as the causative gene for VKCFD1.
- name: VKCFD2
  display_name: VKCFD type 2 (VKORC1 deficiency)
  subtype_term:
    preferred_term: vitamin K-dependent clotting factors, combined deficiency of, type 2
    term:
      id: MONDO:0011837
      label: vitamin K-dependent clotting factors, combined deficiency of, type 2
  description: >-
    VKCFD2 is caused by biallelic pathogenic variants in VKORC1, encoding the
    catalytic subunit of vitamin K epoxide reductase, which regenerates reduced
    vitamin K (the hydroquinone cofactor) required for gamma-carboxylation. The
    same gene harbors gain-of-function variants causing warfarin resistance.
  genes:
  - preferred_term: VKORC1
    term:
      id: hgnc:23663
      label: VKORC1
  evidence:
  - reference: PMID:14765194
    reference_title: "Mutations in VKORC1 cause warfarin resistance and multiple coagulation factor deficiency type 2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      VKORC1 contains missense mutations in both human disorders and in a
      warfarin-resistant rat strain.
    explanation: Rost et al. identified VKORC1 as the gene mutated in VKCFD2, distinguishing it from the GGCX-related VKCFD1.

pathophysiology:
- name: Vitamin K epoxide reductase deficiency (VKCFD2)
  description: >-
    In VKCFD2, biallelic VKORC1 missense variants impair the vitamin K epoxide
    reductase complex, which recycles vitamin K 2,3-epoxide back to the reduced
    vitamin K hydroquinone cofactor. Loss of VKOR activity depletes the reduced
    vitamin K pool needed to drive gamma-carboxylation, upstream of the
    carboxylase reaction itself.
  cell_types:
  - preferred_term: hepatocyte
    term:
      id: CL:0000182
      label: hepatocyte
  biological_processes:
  - preferred_term: vitamin K recycling (vitamin K metabolic process)
    modifier: DECREASED
    term:
      id: GO:0042373
      label: vitamin K metabolic process
  evidence:
  - reference: PMID:14765194
    reference_title: "Mutations in VKORC1 cause warfarin resistance and multiple coagulation factor deficiency type 2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      This complex recycles vitamin K 2,3-epoxide to vitamin K hydroquinone, a
      cofactor that is essential for the post-translational gamma-carboxylation
      of several blood coagulation factors.
    explanation: VKOR recycling of vitamin K is required to supply the cofactor for carboxylation; its loss in VKCFD2 starves the carboxylase of reduced vitamin K.
  - reference: PMID:14765194
    reference_title: "Mutations in VKORC1 cause warfarin resistance and multiple coagulation factor deficiency type 2."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Overexpression of wild-type VKORC1, but not VKORC1 carrying the VKCFD2
      mutation, leads to a marked increase in VKOR activity, which is sensitive
      to warfarin inhibition.
    explanation: Functional expression confirms the VKCFD2 VKORC1 variant abolishes VKOR enzymatic activity.
  downstream:
  - target: Defective gamma-carboxylation of vitamin K-dependent proteins
    description: Reduced vitamin K hydroquinone cannot be supplied to the carboxylase, blocking carboxylation downstream.
- name: Gamma-glutamyl carboxylase deficiency (VKCFD1)
  description: >-
    In VKCFD1, biallelic GGCX variants reduce the activity of gamma-glutamyl
    carboxylase, the endoplasmic reticulum enzyme that carboxylates glutamate
    residues of vitamin K-dependent proteins. Different GGCX variants
    differentially impair carboxylation of individual substrates, which accounts
    for the variable combination of hemorrhagic and non-hemorrhagic phenotypes.
  cell_types:
  - preferred_term: hepatocyte
    term:
      id: CL:0000182
      label: hepatocyte
  biological_processes:
  - preferred_term: gamma-carboxylation (peptidyl-glutamic acid carboxylation)
    modifier: DECREASED
    term:
      id: GO:0017187
      label: peptidyl-glutamic acid carboxylation
  evidence:
  - reference: PMID:9845520
    reference_title: "A missense mutation in gamma-glutamyl carboxylase gene causes combined deficiency of all vitamin K-dependent blood coagulation factors."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      The mutated carboxylase protein expressed in Drosophila cells was stable
      but demonstrated threefold reduced activity compared with WT carboxylase,
      confirming that the L394R mutation results in a defective carboxylase.
    explanation: Functional expression demonstrates that the causative GGCX variant directly reduces carboxylase activity.
  - reference: PMID:34816548
    reference_title: "GGCX variants leading to biallelic deficiency to gamma-carboxylate GRP cause skin laxity in VKCFD1 patients."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      we have analyzed 20 pathogenic GGCX variants on their ability to
      γ-carboxylate six non-hemostatic VKD proteins
    explanation: GGCX variants differentially affect carboxylation of distinct vitamin K-dependent substrates, the basis of phenotypic heterogeneity in VKCFD1.
  downstream:
  - target: Defective gamma-carboxylation of vitamin K-dependent proteins
    description: Reduced carboxylase activity directly prevents gamma-carboxylation of its protein substrates.
- name: Defective gamma-carboxylation of vitamin K-dependent proteins
  description: >-
    Both enzymatic defects converge on impaired gamma-carboxylation, the
    post-translational addition of a carboxyl group to specific glutamate
    residues. Gamma-carboxyglutamate residues are required for the calcium-
    dependent membrane binding and biological activity of vitamin K-dependent
    proteins. GGCX carboxylates 15 different vitamin K-dependent proteins
    spanning coagulation, calcification, and cell signaling.
  cell_types:
  - preferred_term: hepatocyte
    term:
      id: CL:0000182
      label: hepatocyte
  biological_processes:
  - preferred_term: peptidyl-glutamic acid carboxylation
    modifier: DECREASED
    term:
      id: GO:0017187
      label: peptidyl-glutamic acid carboxylation
  evidence:
  - reference: PMID:35054981
    reference_title: "The Role of GRP and MGP in the Development of Non-Hemorrhagic VKCFD1 Phenotypes."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      The GGCX enzyme catalyzes the γ-carboxylation of 15 different vitamin K
      dependent (VKD) proteins, which have function in blood coagulation,
      calcification, and cell signaling.
    explanation: Establishes that gamma-carboxylation by GGCX activates a broad set of vitamin K-dependent proteins beyond coagulation.
  downstream:
  - target: Undercarboxylated, functionally defective coagulation factors
    description: Coagulation factors II, VII, IX and X lack the Gla residues needed for procoagulant activity.
  - target: Undercarboxylation of non-hemostatic vitamin K-dependent proteins
    description: Matrix Gla protein, Gla-rich protein and osteocalcin are also undercarboxylated, driving non-hemorrhagic features in VKCFD1.
- name: Undercarboxylated, functionally defective coagulation factors
  description: >-
    Undercarboxylated factors II, VII, IX and X (and the anticoagulants protein
    C and protein S) are secreted but cannot bind calcium and phospholipid
    membranes normally, producing a functional combined deficiency of vitamin
    K-dependent coagulation factors and impaired blood coagulation.
  cell_types:
  - preferred_term: hepatocyte
    term:
      id: CL:0000182
      label: hepatocyte
  biological_processes:
  - preferred_term: blood coagulation
    modifier: ABNORMAL
    term:
      id: GO:0007596
      label: blood coagulation
  evidence:
  - reference: PMID:19141161
    reference_title: "Familial deficiency of vitamin K-dependent clotting factors."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      A rare inherited form of defective gamma-carboxylation resulting in early
      onset of bleeding was first described by McMillan and Roberts in 1966 and
      subsequently has been termed 'vitamin K-dependent clotting factor
      deficiency' (VKCFD).
    explanation: Links defective gamma-carboxylation to the combined clotting factor deficiency and bleeding phenotype.
  downstream:
  - target: Bleeding diathesis
    description: Deficient procoagulant activity manifests clinically as a bleeding tendency.
  - target: Intracranial hemorrhage
    description: Severe coagulation-factor dysfunction can cause life-threatening intracranial bleeding.
    evidence:
    - reference: PMID:34558179
      reference_title: "GGCX-related congenital combined vitamin K-dependent clotting factors deficiency-1: Description of a fetus with chondrodysplasia punctata."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        stippled epiphyses, and brain abnormalities suggestive of a brain
        hemorrhage.
      explanation: The reported GGCX-related VKCFD fetus had brain abnormalities suggestive of hemorrhage.
  - target: Reduced prothrombin (factor II)
    description: Factor II is one of the vitamin K-dependent clotting factors with deficient activity.
    evidence:
    - reference: PMID:19141161
      reference_title: "Familial deficiency of vitamin K-dependent clotting factors."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: >-
        Combined deficiency of vitamin K-dependent clotting factors II, VII, IX
        and X (and proteins C, S, and Z)
      explanation: This defines factor II as one of the deficient vitamin K-dependent clotting factors.
  - target: Reduced factor VII activity
    description: Factor VII activity is reduced as part of the combined vitamin K-dependent factor deficiency.
    evidence:
    - reference: PMID:19141161
      reference_title: "Familial deficiency of vitamin K-dependent clotting factors."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: >-
        Combined deficiency of vitamin K-dependent clotting factors II, VII, IX
        and X (and proteins C, S, and Z)
      explanation: This defines factor VII as one of the deficient vitamin K-dependent clotting factors.
  - target: Reduced factor IX activity
    description: Factor IX activity is reduced as part of the combined vitamin K-dependent factor deficiency.
    evidence:
    - reference: PMID:19141161
      reference_title: "Familial deficiency of vitamin K-dependent clotting factors."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: >-
        Combined deficiency of vitamin K-dependent clotting factors II, VII, IX
        and X (and proteins C, S, and Z)
      explanation: This defines factor IX as one of the deficient vitamin K-dependent clotting factors.
  - target: Reduced factor X activity
    description: Factor X activity is reduced as part of the combined vitamin K-dependent factor deficiency.
    evidence:
    - reference: PMID:19141161
      reference_title: "Familial deficiency of vitamin K-dependent clotting factors."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: >-
        Combined deficiency of vitamin K-dependent clotting factors II, VII, IX
        and X (and proteins C, S, and Z)
      explanation: This defines factor X as one of the deficient vitamin K-dependent clotting factors.
  - target: Prolonged prothrombin time
    description: Reduced extrinsic/common-pathway vitamin K-dependent factors prolong the prothrombin time.
    evidence:
    - reference: ORPHA:98434
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "HP:0008151 | Prolonged prothrombin time | Frequent (79-30%)"
      explanation: Orphanet lists prolonged prothrombin time as a frequent VKCFD laboratory phenotype.
  - target: Prolonged partial thromboplastin time
    description: Reduced intrinsic/common-pathway vitamin K-dependent factors prolong the partial thromboplastin time.
    evidence:
    - reference: ORPHA:98434
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "HP:0003645 | Prolonged partial thromboplastin time | Frequent (79-30%)"
      explanation: Orphanet lists prolonged partial thromboplastin time as a frequent VKCFD laboratory phenotype.
- name: Undercarboxylation of non-hemostatic vitamin K-dependent proteins
  description: >-
    In VKCFD1, reduced gamma-carboxylation of matrix Gla protein (MGP) and
    Gla-rich protein (GRP) impairs their function as inhibitors of ectopic
    calcification and modulators of connective tissue, producing skin laxity,
    skeletal dysmorphology, and cardiovascular calcification. The pattern depends
    on which substrates a given GGCX variant fails to carboxylate. MGP and GRP
    are produced extrahepatically by chondrocytes, vascular smooth muscle cells,
    and dermal fibroblasts, which are the sites of the non-hemostatic pathology.
  cell_types:
  - preferred_term: chondrocyte
    term:
      id: CL:0000138
      label: chondrocyte
  - preferred_term: vascular smooth muscle cell
    term:
      id: CL:0000359
      label: vascular associated smooth muscle cell
  - preferred_term: dermal fibroblast
    term:
      id: CL:0002620
      label: skin fibroblast
  biological_processes:
  - preferred_term: peptidyl-glutamic acid carboxylation
    modifier: DECREASED
    term:
      id: GO:0017187
      label: peptidyl-glutamic acid carboxylation
  evidence:
  - reference: PMID:34816548
    reference_title: "GGCX variants leading to biallelic deficiency to gamma-carboxylate GRP cause skin laxity in VKCFD1 patients."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      We observed that GGCX variants causing markedly reduced γ-carboxylation of
      Gla rich protein (GRP) in vitro were reported in patients with skin laxity.
    explanation: Directly links undercarboxylation of the non-hemostatic protein GRP to the skin-laxity phenotype of VKCFD1.
  - reference: PMID:35054981
    reference_title: "The Role of GRP and MGP in the Development of Non-Hemorrhagic VKCFD1 Phenotypes."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      The major manifestation of non-hemorrhagic phenotypes in VKCFD1 patients
      are mineralization defects.
    explanation: Establishes that the non-hemorrhagic VKCFD1 phenotypes are driven by mineralization defects from undercarboxylated MGP/GRP.
  downstream:
  - target: Cutis laxa / skin laxity
    description: Reduced GRP gamma-carboxylation is linked to the VKCFD1 skin-laxity phenotype.
    evidence:
    - reference: PMID:34816548
      reference_title: "GGCX variants leading to biallelic deficiency to gamma-carboxylate GRP cause skin laxity in VKCFD1 patients."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        In addition to bleedings, some VKCFD1 patients develop skin laxity and
        skeletal dysmorphologies.
      explanation: This supports skin laxity as a VKCFD1 manifestation connected to non-hemostatic GGCX substrate defects.
  - target: Epiphyseal stippling (chondrodysplasia punctata)
    description: Impaired vitamin K-dependent mineralization biology contributes to epiphyseal stippling.
    evidence:
    - reference: PMID:34558179
      reference_title: "GGCX-related congenital combined vitamin K-dependent clotting factors deficiency-1: Description of a fetus with chondrodysplasia punctata."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        Pathological examination showed a Binder phenotype, hypoplastic distal
        phalanges, stippled epiphyses, and brain abnormalities suggestive of a
        brain hemorrhage.
      explanation: The fetal VKCFD case directly supports stippled epiphyses as a mineralization phenotype.
  - target: Nasal hypoplasia
    description: Mineralization and skeletal dysmorphology can include hypoplastic nasal bone/Binder phenotype.
    evidence:
    - reference: PMID:34558179
      reference_title: "GGCX-related congenital combined vitamin K-dependent clotting factors deficiency-1: Description of a fetus with chondrodysplasia punctata."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        Pathological examination showed a Binder phenotype, hypoplastic distal
        phalanges, stippled epiphyses, and brain abnormalities suggestive of a
        brain hemorrhage.
      explanation: Binder phenotype and skeletal dysmorphology support the nasal hypoplasia phenotype.

phenotypes:
- name: Bleeding diathesis
  category: Clinical
  description: >-
    Spectrum of bleeding symptoms ranging from mild to severe, often beginning in
    the neonatal period, occurring spontaneously or with surgery and sometimes
    life-threatening.
  phenotype_term:
    preferred_term: Abnormal bleeding
    term:
      id: HP:0001892
      label: Abnormal bleeding
  evidence:
  - reference: PMID:40541254
    reference_title: "Hereditary Combined Deficiency of the Vitamin K-Dependent Coagulation Factors."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The condition presents with a spectrum of bleeding symptoms ranging from
      mild to severe, often beginning in the neonatal period.
    explanation: Directly supports the combined-deficiency bleeding diathesis as the cardinal manifestation of VKCFD.
- name: Intracranial hemorrhage
  category: Clinical
  description: >-
    Severe, potentially life-threatening bleeding can occur, including
    intracranial hemorrhage; a brain hemorrhage was identified in a prenatally
    diagnosed VKCFD fetus.
  phenotype_term:
    preferred_term: Intracranial hemorrhage
    term:
      id: HP:0002170
      label: Intracranial hemorrhage
  evidence:
  - reference: PMID:34558179
    reference_title: "GGCX-related congenital combined vitamin K-dependent clotting factors deficiency-1: Description of a fetus with chondrodysplasia punctata."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      stippled epiphyses, and brain abnormalities suggestive of a brain
      hemorrhage.
    explanation: A prenatally diagnosed GGCX-VKCFD fetus had brain abnormalities suggestive of hemorrhage, supporting intracranial bleeding risk.
- name: Reduced prothrombin (factor II)
  category: Laboratory
  description: >-
    Deficient activity of the vitamin K-dependent procoagulant factor II
    (prothrombin) due to undercarboxylation.
  phenotype_term:
    preferred_term: Abnormality of prothrombin (factor II)
    term:
      id: HP:0012200
      label: Abnormality of prothrombin
  evidence:
  - reference: PMID:19141161
    reference_title: "Familial deficiency of vitamin K-dependent clotting factors."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      Combined deficiency of vitamin K-dependent clotting factors II, VII, IX
      and X (and proteins C, S, and Z)
    explanation: Defines the combined deficiency of factor II among the affected vitamin K-dependent factors.
- name: Reduced factor VII activity
  category: Laboratory
  description: >-
    Deficient activity of the vitamin K-dependent procoagulant factor VII due to
    undercarboxylation.
  phenotype_term:
    preferred_term: Reduced factor VII activity
    term:
      id: HP:0008169
      label: Reduced factor VII activity
  evidence:
  - reference: PMID:19141161
    reference_title: "Familial deficiency of vitamin K-dependent clotting factors."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      Combined deficiency of vitamin K-dependent clotting factors II, VII, IX
      and X (and proteins C, S, and Z)
    explanation: Defines the combined deficiency of factor VII among the affected vitamin K-dependent factors.
- name: Reduced factor IX activity
  category: Laboratory
  description: >-
    Deficient activity of the vitamin K-dependent procoagulant factor IX due to
    undercarboxylation.
  phenotype_term:
    preferred_term: Reduced factor IX activity
    term:
      id: HP:0011858
      label: Reduced factor IX activity
  evidence:
  - reference: PMID:19141161
    reference_title: "Familial deficiency of vitamin K-dependent clotting factors."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      Combined deficiency of vitamin K-dependent clotting factors II, VII, IX
      and X (and proteins C, S, and Z)
    explanation: Defines the combined deficiency of factor IX among the affected vitamin K-dependent factors.
- name: Reduced factor X activity
  category: Laboratory
  description: >-
    Deficient activity of the vitamin K-dependent procoagulant factor X due to
    undercarboxylation.
  phenotype_term:
    preferred_term: Reduced factor X activity
    term:
      id: HP:0008321
      label: Reduced factor X activity
  evidence:
  - reference: PMID:19141161
    reference_title: "Familial deficiency of vitamin K-dependent clotting factors."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      Combined deficiency of vitamin K-dependent clotting factors II, VII, IX
      and X (and proteins C, S, and Z)
    explanation: Defines the combined deficiency of factor X among the affected vitamin K-dependent factors.
- name: Prolonged prothrombin time
  category: Laboratory
  description: Prolonged PT/INR reflects impaired extrinsic and common coagulation pathway activity in VKCFD.
  phenotype_term:
    preferred_term: Prolonged prothrombin time
    term:
      id: HP:0008151
      label: Prolonged prothrombin time
  evidence:
  - reference: ORPHA:98434
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0008151 | Prolonged prothrombin time | Frequent (79-30%)"
    explanation: Orphanet lists prolonged prothrombin time as a frequent laboratory phenotype of hereditary VKCFD.
- name: Prolonged partial thromboplastin time
  category: Laboratory
  description: Prolonged PTT reflects impaired intrinsic and common coagulation pathway activity in VKCFD.
  phenotype_term:
    preferred_term: Prolonged partial thromboplastin time
    term:
      id: HP:0003645
      label: Prolonged partial thromboplastin time
  evidence:
  - reference: ORPHA:98434
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0003645 | Prolonged partial thromboplastin time | Frequent (79-30%)"
    explanation: Orphanet lists prolonged partial thromboplastin time as a frequent laboratory phenotype of hereditary VKCFD.
- name: Cutis laxa / skin laxity
  category: Clinical
  subtype: VKCFD1
  description: >-
    Some VKCFD1 patients develop skin hyperlaxity, attributed to undercarboxylation
    of the non-hemostatic vitamin K-dependent protein Gla-rich protein (GRP).
  phenotype_term:
    preferred_term: Cutis laxa
    term:
      id: HP:0000973
      label: Cutis laxa
  evidence:
  - reference: PMID:34816548
    reference_title: "GGCX variants leading to biallelic deficiency to gamma-carboxylate GRP cause skin laxity in VKCFD1 patients."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      In addition to bleedings, some VKCFD1 patients develop skin laxity and
      skeletal dysmorphologies.
    explanation: Supports skin laxity as a recognized non-hemorrhagic feature of GGCX-related VKCFD1.
- name: Epiphyseal stippling (chondrodysplasia punctata)
  category: Clinical
  subtype: VKCFD1
  description: >-
    Skeletal dysmorphology including brachytelephalangic chondrodysplasia punctata
    with stippled epiphyses, resembling warfarin embryopathy, has been described
    in GGCX-related VKCFD, including a prenatal case.
  phenotype_term:
    preferred_term: Epiphyseal stippling
    term:
      id: HP:0010655
      label: Epiphyseal stippling
  evidence:
  - reference: PMID:34558179
    reference_title: "GGCX-related congenital combined vitamin K-dependent clotting factors deficiency-1: Description of a fetus with chondrodysplasia punctata."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Pathological examination showed a Binder phenotype, hypoplastic distal
      phalanges, stippled epiphyses, and brain abnormalities suggestive of a
      brain hemorrhage.
    explanation: A prenatally diagnosed GGCX-VKCFD fetus exhibited stippled epiphyses (chondrodysplasia punctata).
- name: Nasal hypoplasia
  category: Clinical
  subtype: VKCFD1
  description: >-
    Midface and nasal hypoplasia (Binder phenotype, absent nasal bone) can occur
    in GGCX-related VKCFD as part of the skeletal dysmorphology, resembling the
    warfarin embryopathy pattern.
  phenotype_term:
    preferred_term: Aplasia/Hypoplasia of the nasal bone
    term:
      id: HP:0010940
      label: Aplasia/Hypoplasia of the nasal bone
  evidence:
  - reference: PMID:34558179
    reference_title: "GGCX-related congenital combined vitamin K-dependent clotting factors deficiency-1: Description of a fetus with chondrodysplasia punctata."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      a male fetus with a brachytelephalangic chondrodysplasia punctata (CDP),
      absence of nasal bone, growth restriction, and bilateral ventriculomegaly
      at 18 weeks of gestation.
    explanation: Documents absent nasal bone (nasal hypoplasia / Binder phenotype) in a GGCX-VKCFD fetus.

genetic:
- name: GGCX pathogenic variants (VKCFD1)
  gene_term:
    preferred_term: GGCX
    term:
      id: hgnc:4247
      label: GGCX
  association: Causative
  relationship_type: CAUSATIVE
  variant_origin: GERMLINE
  subtype: VKCFD1
  notes: >-
    VKCFD1 results from biallelic point mutations in the gamma-glutamyl
    carboxylase gene (GGCX). The first reported example was a homozygous L394R
    missense variant in a consanguineous kindred.
  evidence:
  - reference: PMID:19141161
    reference_title: "Familial deficiency of vitamin K-dependent clotting factors."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      VKCFD1, which is associated with point mutations in the
      gamma-glutamylcarboxylase gene (GGCX)
    explanation: Establishes GGCX point mutations as the genetic basis of VKCFD1.
  variants:
  - name: GGCX p.Leu394Arg (L394R) missense variant
    description: >-
      Homozygous GGCX missense variant in exon 9 at residue 394 (Leu->Arg); the
      first reported VKCFD-causing GGCX mutation, segregating recessively in a
      consanguineous kindred and reducing carboxylase activity ~threefold.
    evidence:
    - reference: PMID:9845520
      reference_title: "A missense mutation in gamma-glutamyl carboxylase gene causes combined deficiency of all vitamin K-dependent blood coagulation factors."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        All 4 patients were homozygous for a point mutation in exon 9 that
        resulted in the conversion of an arginine codon (CTG) to leucine codon
        (CGG) at residue 394.
      explanation: Documents the first reported GGCX variant causing VKCFD1 and its recessive segregation.
- name: VKORC1 pathogenic variants (VKCFD2)
  gene_term:
    preferred_term: VKORC1
    term:
      id: hgnc:23663
      label: VKORC1
  association: Causative
  relationship_type: CAUSATIVE
  variant_origin: GERMLINE
  subtype: VKCFD2
  notes: >-
    VKCFD2 results from biallelic missense variants in VKORC1. The same gene
    harbors distinct variants causing autosomal dominant coumarin (warfarin)
    resistance, illustrating allelic heterogeneity.
  evidence:
  - reference: PMID:14765194
    reference_title: "Mutations in VKORC1 cause warfarin resistance and multiple coagulation factor deficiency type 2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Mutations in VKORC1 cause warfarin resistance and multiple coagulation
      factor deficiency type 2.
    explanation: Identifies VKORC1 missense mutations as the cause of VKCFD2 (multiple coagulation factor deficiency type 2).

treatments:
- name: Vitamin K supplementation
  description: >-
    High oral (or parenteral) doses of vitamin K are the primary treatment and
    prophylaxis, usually resulting in partial correction of the factor
    deficiency. Response depends on residual enzyme activity.
  therapeutic_modality: SMALL_MOLECULE
  target_mechanisms:
  - target: Defective gamma-carboxylation of vitamin K-dependent proteins
    treatment_effect: RESTORES
    description: Supraphysiologic vitamin K can partially restore the reduced vitamin K cofactor pool and drive residual carboxylase activity.
  treatment_term:
    preferred_term: nutritional supplementation
    term:
      id: MAXO:0000106
      label: nutritional supplementation
    therapeutic_agent:
    - preferred_term: vitamin K1 (phylloquinone)
      term:
        id: CHEBI:18067
        label: phylloquinone
  evidence:
  - reference: PMID:19141161
    reference_title: "Familial deficiency of vitamin K-dependent clotting factors."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      Therapy includes high oral doses of vitamin K for prophylaxis, usually
      resulting in partial correction of factor deficiency
    explanation: Establishes high-dose vitamin K as the mainstay of VKCFD prophylaxis with partial response.
- name: Fresh frozen plasma transfusion
  description: >-
    Transfusion of fresh frozen plasma is often required during surgery or in
    cases of severe bleeding to replace the deficient vitamin K-dependent factors.
  target_mechanisms:
  - target: Undercarboxylated, functionally defective coagulation factors
    treatment_effect: BYPASSES
    description: FFP supplies functional vitamin K-dependent coagulation factors, bypassing the patient's defective endogenous factors.
  treatment_term:
    preferred_term: Fresh Frozen Plasma Transfusion
    term:
      id: NCIT:C116475
      label: Fresh Frozen Plasma Transfusion
  evidence:
  - reference: PMID:40541254
    reference_title: "Hereditary Combined Deficiency of the Vitamin K-Dependent Coagulation Factors."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      with transfusions of fresh frozen plasma often required during surgery or
      in cases of severe bleeding.
    explanation: Supports fresh frozen plasma transfusion for acute or perioperative bleeding in VKCFD.
- name: Prothrombin complex concentrate
  description: >-
    Prothrombin complex concentrates (PCCs), which contain the vitamin
    K-dependent factors II, VII, IX and X, can be used episodically, including in
    combination with recombinant activated factor VII and vitamin K.
  target_mechanisms:
  - target: Undercarboxylated, functionally defective coagulation factors
    treatment_effect: BYPASSES
    description: PCCs supply functional factors II, VII, IX and X, bypassing the patient's undercarboxylated endogenous factors.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
  evidence:
  - reference: PMID:40541254
    reference_title: "Hereditary Combined Deficiency of the Vitamin K-Dependent Coagulation Factors."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      alternative therapies such as prothrombin complex concentrates (PCCs) or a
      combination of recombinant activated factor VII and vitamin K may be
      considered.
    explanation: Supports prothrombin complex concentrate as an alternative therapy for VKCFD bleeding.
- name: Recombinant activated factor VII (rFVIIa)
  description: >-
    Recombinant activated factor VII (rFVIIa, eptacog alfa) can be considered for
    life-threatening or refractory bleeding, in combination with vitamin K, to
    bypass the deficient vitamin K-dependent coagulation factors.
  target_mechanisms:
  - target: Undercarboxylated, functionally defective coagulation factors
    treatment_effect: BYPASSES
    description: rFVIIa promotes thrombin generation independently of the patient's undercarboxylated factors, bypassing the functional combined factor deficiency.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: recombinant activated factor VII (eptacog alfa)
      term:
        id: NCIT:C81125
        label: Eptacog Alfa
  evidence:
  - reference: PMID:40541254
    reference_title: "Hereditary Combined Deficiency of the Vitamin K-Dependent Coagulation Factors."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      alternative therapies such as prothrombin complex concentrates (PCCs) or a
      combination of recombinant activated factor VII and vitamin K may be
      considered.
    explanation: Supports recombinant activated factor VII as an alternative therapy for VKCFD bleeding.
📚

References & Deep Research

References

2
PMID:40541254
Hereditary Combined Deficiency of the Vitamin K-Dependent Coagulation Factors.
No top-level findings curated for this source.
PMID:19141161
Familial deficiency of vitamin K-dependent clotting factors.
No top-level findings curated for this source.

Deep Research

1
Falcon ▸
1. Disease Information
Edison Scientific Literature 41 citations 2026-06-08T17:04:18.724929

1. Disease Information

1.1 What is the disease?

Hereditary combined vitamin K–dependent clotting factors deficiency (VKCFD) is a rare congenital bleeding disorder characterized by variably decreased activities of vitamin K–dependent clotting factors II, VII, IX, and X, plus reduced natural anticoagulants protein C, protein S, and protein Z, due to defective vitamin K–dependent γ-carboxylation. (napolitano2010hereditarycombineddeficiency pages 1-2)

A more recent narrative review similarly defines inherited VKCFD as an autosomal recessive genetic disease with impaired levels of multiple coagulation factors (II, VII, IX, X) and natural anticoagulants (proteins C and S), and notes diagnostic delay because it can mimic acquired vitamin K deficiency. (perrone2025clinicallaboratoryand pages 1-2)

1.2 Key identifiers (OMIM/Orphanet/ICD/MeSH/MONDO)

  • Disease-level identifiers (OMIM disease/Orphanet/MONDO/MeSH/ICD): Not explicitly provided in the retrieved full-text evidence set. (Evidence limitation)
  • Gene identifiers (provided in evidence):
  • GGCX: OMIM gene entry referenced as OMIM 277450 in the Perrone 2025 review. (perrone2025clinicallaboratoryand pages 1-2)
  • VKORC1: OMIM gene entry referenced as OMIM 607473 in the Perrone 2025 review. (perrone2025clinicallaboratoryand pages 1-2)

1.3 Synonyms / alternative names

  • Hereditary combined deficiency of the vitamin K–dependent clotting factors (VKCFD) (napolitano2010hereditarycombineddeficiency pages 1-2)
  • Inherited vitamin K–dependent coagulation factors deficiency (perrone2025clinicallaboratoryand pages 1-2)
  • Vitamin K-dependent coagulation factor deficiency type 1 (VKCFD1; GGCX) and type 2 (VKCFD2; VKORC1) (perrone2025clinicallaboratoryand pages 1-2, napolitano2010hereditarycombineddeficiency pages 1-2)

1.4 Evidence source type

Most disease information for VKCFD is derived from aggregated disease-level resources and reviews that compile small case series and single case reports, reflecting the ultra-rare nature of the condition. (napolitano2010hereditarycombineddeficiency pages 1-2)

2. Etiology

2.1 Disease causal factors

Primary cause (Mendelian): biallelic pathogenic variants in either: * GGCX (γ-glutamyl carboxylase) → VKCFD type 1 (VKCFD1) (perrone2025clinicallaboratoryand pages 1-2, napolitano2010hereditarycombineddeficiency pages 1-2) * VKORC1 (vitamin K epoxide reductase complex subunit 1) → VKCFD type 2 (VKCFD2) (perrone2025clinicallaboratoryand pages 1-2, napolitano2010hereditarycombineddeficiency pages 1-2)

Mechanistic cause is defective vitamin K–dependent γ-carboxylation, producing undercarboxylated, low-activity coagulation factors and other vitamin K–dependent proteins. (napolitano2010hereditarycombineddeficiency pages 2-3, raharimanana2025hereditarycombineddeficiency pages 1-2)

2.2 Risk factors

  • Genetic: autosomal recessive inheritance; consanguinity is frequent and homozygous variants account for >50% of reported cases in one review. (raharimanana2025hereditarycombineddeficiency pages 3-3)
  • Acquired modifiers of bleeding in affected individuals (not causal for the Mendelian disorder): antibiotics and anticonvulsants may worsen the bleeding pattern (likely via lowering vitamin K availability). (napolitano2010hereditarycombineddeficiency pages 2-3)

2.3 Protective factors

No specific protective genetic variants were identified in the retrieved evidence. (Evidence limitation)

2.4 Gene–environment interactions

Clinical severity depends on residual γ-carboxylation capacity and vitamin K availability, so environmental or iatrogenic reductions in vitamin K can exacerbate bleeding in genetically affected individuals. (napolitano2010hereditarycombineddeficiency pages 2-3, perrone2025clinicallaboratoryand pages 5-5)

3. Phenotypes

3.1 Core bleeding phenotypes (HPO suggestions)

  • Mucocutaneous bleeding (e.g., easy bruising, epistaxis, GI bleeding) (napolitano2010hereditarycombineddeficiency pages 1-2, perrone2025clinicallaboratoryand pages 5-5)
  • HPO: Epistaxis (HP:0000421), Easy bruising (HP:0000978), Gastrointestinal hemorrhage (HP:0002239)
  • Postoperative/surgical bleeding (raharimanana2025hereditarycombineddeficiency pages 7-8, napolitano2010hereditarycombineddeficiency pages 2-3)
  • HPO: Abnormal bleeding (HP:0001892)
  • Umbilical cord bleeding (neonatal) (napolitano2010hereditarycombineddeficiency pages 1-2, napolitano2010hereditarycombineddeficiency pages 2-3)
  • HPO: Umbilical hemorrhage (HP:0010705)
  • Intracranial hemorrhage (ICH) (early-life severe outcome) (raharimanana2025hereditarycombineddeficiency pages 7-8, napolitano2010hereditarycombineddeficiency pages 2-3)
  • HPO: Intracranial hemorrhage (HP:0002170)
  • Hemarthrosis is rare (napolitano2010hereditarycombineddeficiency pages 2-3)
  • HPO: Hemarthrosis (HP:0001896)

3.2 Phenotype frequencies and severity (recent quantitative data)

In a 2025 review/case series (61 patients), 74% of patients had bleeding; among bleeding patients 60% had mucocutaneous bleeding and 26% had bleeding linked to surgery/antibiotics. (raharimanana2025hereditarycombineddeficiency pages 7-8)

In the same series, intracranial hemorrhage occurred in 27% overall, and 92% of intracranial hemorrhages occurred before age 1 (highlighting an early-life critical period). (raharimanana2025hereditarycombineddeficiency pages 7-8)

Laboratory severity correlates with clinical severity; one review categorized “significant deficiency” using hemorrhagic thresholds (FII <20%, FVII <20%, FIX <40%, FX <30%), present in 38/47 (81%) in the subset analyzed. (raharimanana2025hereditarycombineddeficiency pages 7-8)

3.3 Extra-hemorrhagic phenotypes (particularly VKCFD1/GGCX)

Non-hemorrhagic features can arise from impaired γ-carboxylation of extrahepatic VK-dependent proteins (e.g., osteocalcin, MGP, Gas6). (napolitano2010hereditarycombineddeficiency pages 2-3, raharimanana2025hereditarycombineddeficiency pages 1-2)

A 2025 series reported non-hemorrhagic features in 55% of GGCX cases and 0% of VKORC1 cases; phenotypes included Keutel-like syndrome, PXE-like features, and subclinical atherosclerosis. (raharimanana2025hereditarycombineddeficiency pages 7-8)

HPO suggestions: * Osteoporosis (HP:0000939) / Reduced bone mineral density (HP:0004349) (napolitano2010hereditarycombineddeficiency pages 2-3, perrone2025clinicallaboratoryand pages 5-5) * Midface hypoplasia (HP:0000348) (perrone2025clinicallaboratoryand pages 3-5) * Patent ductus arteriosus (HP:0001643) / Atrial septal defect (HP:0001631) / Ventricular septal defect (HP:0001629) (perrone2025clinicallaboratoryand pages 3-5) * Cutis laxa / skin laxity (HP:0000973) and PXE-like findings (ghosh2022ggcxvariantsleading pages 1-2, raharimanana2025hereditarycombineddeficiency pages 2-3) * Angioid streaks (HP:0001105) (raharimanana2025hereditarycombineddeficiency pages 2-3)

3.4 Quality of life impact

An Orphanet review states the overall prognosis is good and VKCFD “has only a small impact on the quality of life” when effective therapeutic options are available, but acknowledges life-threatening neonatal bleeding in severe cases. (napolitano2010hereditarycombineddeficiency pages 1-2)

4. Genetic / Molecular Information

4.1 Causal genes and inheritance

  • Autosomal recessive inheritance (napolitano2010hereditarycombineddeficiency pages 1-2, napolitano2010hereditarycombineddeficiency pages 2-3)
  • Causal genes: GGCX (VKCFD1) and VKORC1 (VKCFD2) (perrone2025clinicallaboratoryand pages 1-2, napolitano2010hereditarycombineddeficiency pages 1-2)

4.2 Pathogenic variant spectrum and genotype–phenotype considerations

  • GGCX: at least 34 (and approximately 40) GGCX mutations are reported across reviews; variants are often point mutations and occur as homozygous or compound heterozygous. (perrone2025clinicallaboratoryand pages 2-3, perrone2025clinicallaboratoryand pages 3-5)
  • VKORC1: a recurrent homozygous missense variant c.292C>T (p.Arg98Trp; R98W) is reported in multiple unrelated families and causes mislocalization/degradation with loss of activity. (perrone2025clinicallaboratoryand pages 3-5, napolitano2010hereditarycombineddeficiency pages 2-3)

4.3 Molecular mechanism (vitamin K cycle, γ-carboxylation, PIVKA)

γ-carboxylation occurs in the ER: GGCX converts Glu to Gla residues in VK-dependent proteins using reduced vitamin K (vitamin K hydroquinone), generating vitamin K epoxide; VKORC1 regenerates reduced vitamin K, constituting the “vitamin K cycle.” (napolitano2010hereditarycombineddeficiency pages 2-3, perrone2025clinicallaboratoryand pages 2-3, berkner2022vitaminkdependentprotein pages 1-2)

Impaired γ-carboxylation leads to undercarboxylated proteins termed PIVKA (proteins induced by vitamin K absence or antagonism). (raharimanana2025hereditarycombineddeficiency pages 1-2)

The retrieved figure evidence shows the vitamin K cycle and relationship of GGCX/VKORC1 to Glu→Gla modification. (berkner2022vitaminkdependentprotein media c8e964e8, berkner2022vitaminkdependentprotein media e8dfcf7b)

4.4 Variable response to vitamin K therapy (precision management concept)

Not all VKCFD1 patients normalize factor activities with high-dose vitamin K. A mechanistic study categorized GGCX mutations into vitamin K “responders” and “low responders,” supporting genotype-informed expectations for vitamin K efficacy. (ghosh2021ggcxmutationsshow pages 1-2)

A genotype–phenotype analysis reported that some GGCX variants affecting the KH2 (reduced vitamin K) binding/docking site show severely reduced γ-carboxylation that cannot be rescued by vitamin K administration. (ghosh2022ggcxvariantsleading pages 1-2)

Suggested ontology terms: * GO biological processes: vitamin K metabolic process; protein gamma-carboxylation; blood coagulation (supported conceptually by mechanistic descriptions) (napolitano2010hereditarycombineddeficiency pages 2-3, perrone2025clinicallaboratoryand pages 2-3) * Cellular component: endoplasmic reticulum membrane (GGCX is ER membrane-localized) (perrone2025clinicallaboratoryand pages 2-3) * Cell types (CL): hepatocyte (major site of hepatic coagulation factor synthesis) (berkner2022vitaminkdependentprotein pages 1-2)

5. Environmental Information

VKCFD is a genetic disorder; however, vitamin K status is influenced by diet and microbiome. Antibiotics can reduce microbial vitamin K production, potentially worsening bleeding in affected individuals. (napolitano2010hereditarycombineddeficiency pages 2-3)

Microbial and dietary sources of vitamin K2 (menaquinones) include various bacteria; fermentation products (e.g., natto) can provide menaquinones, which is relevant background for environmental modulation of vitamin K availability (though not proven as a disease-modifying intervention in VKCFD). (sadler2024beyondthecoagulation pages 1-3)

6. Mechanism / Pathophysiology

6.1 Causal chain (upstream → downstream)

  1. Biallelic pathogenic variants in GGCX (VKCFD1) or VKORC1 (VKCFD2). (perrone2025clinicallaboratoryand pages 1-2, napolitano2010hereditarycombineddeficiency pages 1-2)
  2. Reduced γ-carboxylation of vitamin K–dependent proteins in the ER due to deficient GGCX activity or reduced recycling of vitamin K hydroquinone by VKORC1. (napolitano2010hereditarycombineddeficiency pages 2-3, perrone2025clinicallaboratoryand pages 2-3)
  3. Undercarboxylated/low-activity coagulation factors II, VII, IX, X (and proteins C/S/Z) → prolonged PT/INR and aPTT and clinical bleeding. (perrone2025clinicallaboratoryand pages 1-2, perrone2025clinicallaboratoryand pages 5-6)
  4. Undercarboxylation of extrahemostatic VK-dependent proteins (e.g., MGP, osteocalcin, GRP) → skeletal, cardiovascular, skin/ocular PXE-like manifestations in a subset, particularly VKCFD1. (napolitano2010hereditarycombineddeficiency pages 2-3, ghosh2022ggcxvariantsleading pages 1-2, raharimanana2025hereditarycombineddeficiency pages 7-8)

6.2 Biochemical abnormalities

  • Reduced factor activities and accumulation of undercarboxylated proteins (PIVKA). (raharimanana2025hereditarycombineddeficiency pages 1-2)
  • PIVKA-II (des-γ-carboxy prothrombin/DCP) can be used as an early indirect marker of vitamin K status but is not specific for hereditary vs acquired causes. (perrone2025clinicallaboratoryand pages 5-6, raharimanana2025hereditarycombineddeficiency pages 3-3)

7. Anatomical Structures Affected

7.1 Organ systems

  • Hematologic/hemostatic system: primary clinical impact via bleeding. (napolitano2010hereditarycombineddeficiency pages 1-2)
  • Central nervous system: risk of intracranial hemorrhage, especially in infancy. (raharimanana2025hereditarycombineddeficiency pages 7-8, napolitano2010hereditarycombineddeficiency pages 2-3)
  • Skin/eye: PXE-like changes/skin laxity and ocular findings (e.g., angioid streaks). (ghosh2022ggcxvariantsleading pages 1-2, raharimanana2025hereditarycombineddeficiency pages 2-3)
  • Skeletal system: reduced bone mass/osteoporosis, chondrodysplasia punctata-like anomalies. (perrone2025clinicallaboratoryand pages 3-5, perrone2025clinicallaboratoryand pages 5-5)
  • Cardiovascular system: congenital heart defects in some GGCX-related cases. (perrone2025clinicallaboratoryand pages 3-5)

UBERON suggestions (examples): * Brain (UBERON:0000955), Skin (UBERON:0002097), Bone tissue (UBERON:0002481), Heart (UBERON:0000948), Liver (UBERON:0002107; site of hepatic coagulation factor synthesis) (supported by phenotype/mechanism context) (berkner2022vitaminkdependentprotein pages 1-2)

Subcellular (GO cellular component): endoplasmic reticulum membrane (site of γ-carboxylation) (perrone2025clinicallaboratoryand pages 2-3)

8. Temporal Development

8.1 Onset

Onset ranges from neonatal/infantile (severe cases) to later childhood/adulthood (milder cases). (napolitano2010hereditarycombineddeficiency pages 1-2, napolitano2010hereditarycombineddeficiency pages 2-3)

8.2 Progression/course

The clinical course is variable; severe early-life bleeding (including ICH) can be fatal if untreated, but many patients have improved stability with vitamin K supplementation and episodic replacement therapy for procedures/bleeds. (napolitano2010hereditarycombineddeficiency pages 1-2, raharimanana2025hereditarycombineddeficiency pages 3-4)

Critical period: infancy—ICH events in one series occurred predominantly before age 1. (raharimanana2025hereditarycombineddeficiency pages 7-8)

9. Inheritance and Population

9.1 Epidemiology

VKCFD is extremely rare. Estimates in retrieved evidence include: * “Fewer than 30 kindreds worldwide” in earlier literature and sex ratio 1:1. (napolitano2010hereditarycombineddeficiency pages 2-3) * About 30 families described worldwide with broad geographic distribution and no specific ethnic predisposition; consanguinity common and homozygous variants account for more than half of cases. (raharimanana2025hereditarycombineddeficiency pages 3-3) * “Overall 50 affected families thus far” (review-level count). (perrone2025clinicallaboratoryand pages 1-2) * France prevalence estimate ~1 per 1,000,000. (tourbih2025molecularaspectsof pages 9-10)

9.2 Inheritance pattern

Autosomal recessive (napolitano2010hereditarycombineddeficiency pages 1-2, napolitano2010hereditarycombineddeficiency pages 2-3)

Penetrance/expressivity: variable; both bleeding severity and presence of non-hemorrhagic phenotypes vary by genotype and by residual activity. (perrone2025clinicallaboratoryand pages 5-5, vilder2017ggcxassociatedphenotypesan pages 25-26)

10. Diagnostics

10.1 Clinical tests and laboratory abnormalities

Screening coagulation tests: prolonged PT/INR and prolonged/variable aPTT, often with PT more affected due to factor VII’s short half-life. (perrone2025clinicallaboratoryand pages 5-5, raharimanana2025hereditarycombineddeficiency pages 3-3)

Mixing studies: 50:50 mixing typically corrects PT/aPTT, supporting deficiency rather than inhibitor. (perrone2025clinicallaboratoryand pages 5-6, raharimanana2025hereditarycombineddeficiency pages 3-3)

Specific factor assays: low FII, FVII, FIX, FX; normal factor V and generally normal fibrinogen/platelets. Example values include: * FII 17%, FVII 2.9%, FIX 11%, FX 8.5%. (perrone2025clinicallaboratoryand pages 2-3) * FII 30%, FVII 1%, FIX 6%, FX 9%, FV 90% with normal measured vitamin K. (alswij2025hereditarycombineddeficiency pages 4-5)

Biomarkers: * PIVKA-II/DCP rises early and can be measured via immunoassay/ELISA/LC-MS/MS; it is sensitive but not specific for hereditary vs acquired causes. (perrone2025clinicallaboratoryand pages 5-6, raharimanana2025hereditarycombineddeficiency pages 3-3) * Plasma vitamin K1 by HPLC: serum level <0.15 μg/L (non-fasting) suggests deficiency. (raharimanana2025hereditarycombineddeficiency pages 3-3)

Differential diagnosis includes acquired vitamin K deficiency (malabsorption, liver disease, warfarin/rodenticide), DIC, inhibitors, lupus anticoagulant, and other inherited factor deficiencies. (perrone2025clinicallaboratoryand pages 5-5, perrone2025clinicallaboratoryand pages 5-6)

10.2 Genetic testing

Genetic testing is the diagnostic gold standard: sequencing of GGCX (15 exons) and VKORC1 (3 exons) provides definitive diagnosis and subtype classification. (raharimanana2025hereditarycombineddeficiency pages 3-3)

11. Outcome / Prognosis

Prognosis is generally favorable when diagnosed and treated, but severe neonatal bleeding (particularly intracranial hemorrhage) can be life-threatening. (napolitano2010hereditarycombineddeficiency pages 1-2, napolitano2010hereditarycombineddeficiency pages 2-3)

No robust survival curves or standardized QoL instruments (e.g., EQ-5D) were found in the retrieved evidence set. (Evidence limitation)

12. Treatment

12.1 Pharmacotherapy and supportive hemostasis

Vitamin K1 (phylloquinone) supplementation is the mainstay. A recent review provides practical dosing suggestions: * Minor bleeding: 5–20 mg vitamin K IV or orally. (perrone2025clinicallaboratoryand pages 6-7) * Prophylaxis: oral vitamin K1 5–20 mg/day, two to three times weekly; may partially correct factor levels and prevent mucocutaneous bleeding. (perrone2025clinicallaboratoryand pages 6-7) * Poor responders: IV vitamin K about 5–20 mg/week. (perrone2025clinicallaboratoryand pages 6-7)

Antifibrinolytic (adjunct): tranexamic acid (e.g., 1 g every 6 h or weight-based dosing) for minor procedures/mucosal bleeding. (perrone2025clinicallaboratoryand pages 6-7)

Major bleeding/major surgery: * FFP 15–20 mL/kg (perrone2025clinicallaboratoryand pages 6-7, raharimanana2025hereditarycombineddeficiency pages 3-4) * PCC 20–30 U/kg (perrone2025clinicallaboratoryand pages 6-7) * rFVIIa 10–20 μg/kg IV for life-threatening bleeding or complex surgical situations. (perrone2025clinicallaboratoryand pages 6-7)

12.2 Mutation-dependent response (precision treatment concept)

Response to vitamin K can be unpredictable; some mutant proteins have very low/absent activity not rescued by vitamin K. (perrone2025clinicallaboratoryand pages 6-7, ghosh2021ggcxmutationsshow pages 1-2)

MAXO suggestions (examples): * Vitamin K supplementation; plasma transfusion; prothrombin complex concentrate administration; recombinant activated factor VII administration; antifibrinolytic therapy.

13. Prevention

Primary prevention of the Mendelian disorder is not applicable; however, prevention of catastrophic bleeding includes: * Avoiding iatrogenic reductions in vitamin K status (e.g., monitor during antibiotics/other medications). (napolitano2010hereditarycombineddeficiency pages 2-3) * Prenatal/obstetric risk mitigation: vitamin K supplementation in late pregnancy for at-risk mothers has been proposed to reduce neonatal bleeding risk. (raharimanana2025hereditarycombineddeficiency pages 3-4, perrone2025clinicallaboratoryand pages 5-6) * Newborn vitamin K prophylaxis programs are important for preventing vitamin K deficiency bleeding (VKDB) and for reducing diagnostic confusion with hereditary VKCFD. (mathews2025vitaminkdeficiency pages 5-6, perrone2025clinicallaboratoryand pages 5-6)

14. Other Species / Natural Disease

The retrieved evidence does not document naturally occurring VKCFD in companion animals as an established veterinary entity. (Evidence limitation)

However, vitamin K biology is conserved and historically linked to chicken hemorrhagic phenotypes in dietary studies, and vitamin K2 is produced by various bacterial species—relevant for comparative biology and experimental design. (berkner2022vitaminkdependentprotein pages 1-2, sadler2024beyondthecoagulation pages 1-3)

15. Model Organisms and Experimental Systems

  • Mouse: absence/knockout of Ggcx is lethal due to hemorrhage, supporting essentiality of γ-carboxylation for hemostasis. (perrone2025clinicallaboratoryand pages 2-3)
  • Pharmacologic model: warfarin inhibition of VKORC1 mimics impaired vitamin K recycling and is used as an in vivo perturbation model of VK-dependent carboxylation. (berkner2022vitaminkdependentprotein pages 1-2, vilder2017ggcxassociatedphenotypesan pages 1-3)
  • Cell-based models: GGCX−/− cells expressing GGCX variants with in vitro γ-carboxylation assays and ELISA readouts for VK-dependent proteins (used for genotype–phenotype and vitamin K responsiveness studies). (ghosh2022ggcxvariantsleading pages 1-1)

Recent developments and latest research emphasis (2023–2024)

Direct VKCFD-focused primary publications from 2023–2024 were limited in the retrieved evidence set; however, relevant recent developments include: * 2024 in silico mechanistic work on VKORC1 mutations and dynamics (useful for understanding VKORC1 mutational effects that can underlie VKCFD2 and warfarin resistance). URL: https://doi.org/10.3390/ijms25042043 (published Feb 2024). (botnari2024 evidence not extracted into pqac IDs beyond being retrieved; therefore not cited for claims beyond availability) * 2024 broader vitamin K biology review spanning humans and domesticated animals, including sources/biochemistry and relevance to coagulation and calcification phenotypes. URL: https://doi.org/10.3390/cimb46070418 (published Jul 2024). (sadler2024beyondthecoagulation pages 1-3)

Given evidence constraints, the report emphasizes authoritative mechanistic (2022) and aggregated clinical (2025) sources for VKCFD-specific data.

Authoritative quotes from abstracts (supporting key statements)

  • Perrone et al. (Seminars in Thrombosis and Hemostasis; Nov 2025) abstract: “Vitamin K–dependent coagulation factors deficiency (VKCFD) is a rare autosomal recessive genetic disease characterized by impaired levels of multiple coagulation factors (II, VII, IX, and X) and natural anticoagulants (proteins C and S)… reporting overall 50 affected families thus far.” URL: https://doi.org/10.1055/s-0044-1792031 (perrone2025clinicallaboratoryand pages 1-2)
  • Napolitano et al. (Orphanet Journal of Rare Diseases; Jul 2010) abstract: “Hereditary combined vitamin K-dependent clotting factors deficiency (VKCFD) is a rare congenital bleeding disorder resulting from variably decreased levels of coagulation factors II, VII, IX and X…” URL: https://doi.org/10.1186/1750-1172-5-21 (napolitano2010hereditarycombineddeficiency pages 1-2)

Evidence gaps / limitations for this run

  • Disease-level OMIM/Orphanet/MONDO/ICD identifiers were not directly retrievable from the available documents and thus are not provided with citations.
  • High-quality 2023–2024 VKCFD-specific primary clinical reports were not available in the retrieved full text for this run; the most data-rich patient-level epidemiology/phenotype synthesis in evidence is 2025.
  • Formal QoL measures, penetrance estimates, and robust population incidence are not well established in the retrieved evidence.

References

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  27. (vilder2017ggcxassociatedphenotypesan pages 1-3): Eva De Vilder, Jens Debacker, and Olivier Vanakker. Ggcx-associated phenotypes: an overview in search of genotype-phenotype correlations. International Journal of Molecular Sciences, 18:240, Jan 2017. URL: https://doi.org/10.3390/ijms18020240, doi:10.3390/ijms18020240. This article has 61 citations.

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