Inherited or congenital FX deficiency is usually passed on by autosomal recessive inheritance. A person needs to inherit a defective gene from both parents. People who have only one defective gene are asymptomatic, but may have lower FXII levels and can pass the gene on to half their offspring.

In persons with congenital FXII deficiency the condition is lifelong. People affected may want to alert other family members as they may also may carry the gene. A 1994 study of 300 healthy blood donors found that 7 persons (2.3%) had FXII deficiencies with one subject having no detectable FXII (0.3%). This study is at variance with estimates that only 1 in 1,000,000 people has the condition.

The acquired form of FXII deficiency is seen in patients with the nephrotic syndrome, liver disease, sepsis and shock, disseminated intravascular coagulation, and other diseases.

While it is indicated that people with FXII deficiency are generally asymptomatic, studies in women with recurrent miscarriages suggest an association with FXII deficiency.

The condition is of importance in the differential diagnosis to other bleeding disorders, specifically the hemophilias: hemophilia A with a deficiency in factor VIII or antihemophilic globulin, hemophilia B with a deficiency in factor IX (Christmas disease), and hemophilia C with a deficiency in factor XI. Other rare forms of bleeding disorders are also in the differential diagnosis.

There is concern that individuals with FXII deficiency are more prone to thrombophilic disease, however, this is at variance with a long term study from Switzerland.

The prevalence of vWD is about one in 100 individuals. However, the majority of these people do not have symptoms. The prevalence of clinically significant cases is one per 10,000. Because most forms are rather mild, they are detected more often in women, whose bleeding tendency shows during menstruation. It may be more severe or apparent in people with blood type O.

Von Willebrand disease can also affect some breeds of dogs, notably the Doberman Pinscher, and screening is offered for known breeds.

Females possess two X-chromosomes, males have one X and one Y-chromosome. Since the mutations causing the disease are X-linked recessive, a female carrying the defect on one of her X-chromosomes may not be affected by it, as the equivalent allele on her other chromosome should express itself to produce the necessary clotting factors, due to X inactivation. However, the Y-chromosome in the male has no gene for factors VIII or IX. If the genes responsible for production of factor VIII or factor IX present on a male's X-chromosome are deficient there is no equivalent on the Y-chromosome to cancel it out, so the deficient gene is not masked and the disorder will develop.

Since a male receives his single X-chromosome from his mother, the son of a healthy female silently carrying the deficient gene will have a 50% chance of inheriting that gene from her and with it the disease; and if his mother is affected with haemophilia, he will have a 100% chance of being a haemophiliac. In contrast, for a female to inherit the disease, she must receive two deficient X-chromosomes, one from her mother and the other from her father (who must therefore be a haemophiliac himself). Hence haemophilia is far more common among males than females. However, it is possible for female carriers to become mild haemophiliacs due to lyonisation (inactivation) of the X-chromosomes. Haemophiliac daughters are more common than they once were, as improved treatments for the disease have allowed more haemophiliac males to survive to adulthood and become parents. Adult females may experience menorrhagia (heavy periods) due to the bleeding tendency. The pattern of inheritance is criss-cross type. This type of pattern is also seen in colour blindness.

A mother who is a carrier has a 50% chance of passing the faulty X-chromosome to her daughter, while an affected father will always pass on the affected gene to his daughters. A son cannot inherit the defective gene from his father. This is a recessive trait and can be passed on if cases are more severe with carrier. Genetic testing and genetic counselling is recommended for families with haemophilia. Prenatal testing, such as amniocentesis, is available to pregnant women who may be carriers of the condition.

As with all genetic disorders, it is of course also possible for a human to acquire it spontaneously through mutation, rather than inheriting it, because of a new mutation in one of their parents' gametes. Spontaneous mutations account for about 33% of all cases of haemophilia A. About 30% of cases of haemophilia B are the result of a spontaneous gene mutation.

If a female gives birth to a haemophiliac son, either the female is a carrier for the blood disorder or the haemophilia was the result of a spontaneous mutation. Until modern direct DNA testing, however, it was impossible to determine if a female with only healthy children was a carrier or not. Generally, the more healthy sons she bore, the higher the probability that she was not a carrier.

If a male is afflicted with the disease and has children with a female who is not even a carrier, his daughters will be carriers of haemophilia. His sons, however, will not be affected with the disease. The disease is X-linked and the father cannot pass haemophilia through the Y-chromosome. Males with the disorder are then no more likely to pass on the gene to their children than carrier females, though all daughters they sire will be carriers and all sons they father will not have haemophilia (unless the mother is a carrier).

Heterozygous protein C deficiency occurs in 0.14–0.50% of the general population. Based on an estimated carrier rate of 0.2%, a homozygous or compound heterozygous protein C deficiency incidence of 1 per 4 million births could be predicted, although far fewer living patients have been identified. This low prevalence of patients with severe genetic protein C deficiency may be explained by excessive fetal demise, early postnatal deaths before diagnosis, heterogeneity in the cause of low concentrations of protein C among healthy individuals and under-reporting.

The incidence of protein C deficiency in individuals who present with clinical symptoms has been reported to be estimated at 1 in 20,000.

Two Dutch studies have followed hemophilia patients for a number of years. Both studies found that viral infections were common in hemophiliacs due to the frequent blood transfusions which put them at risk of getting blood borne infections such as HIV and hepatitis C. In the latest study which followed patients from 1992 to 2001, the male life expectancy was 59 years. If cases with known viral infections were excluded, the life expectancy was 72, close to that of the general population. 26% of the cases died from AIDS and 22% from hepatitis C.

Hypoprothrombinemia can be the result of a genetic defect, may be acquired as the result of another disease process, or may be an adverse effect of medication. For example, 5-10% of patients with systemic lupus erythematosus exhibit acquired hypoprothrombinemia due to the presence of autoantibodies which bind to prothrombin and remove it from the bloodstream (lupus anticoagulant-hypoprothrombinemia syndrome). The most common viral pathogen that is involved is Adenovirus, with a prevalence of 50% in postviral cases.

Inheritance:

Autosomal recessive condition in which both parents must carry the recessive gene in order to pass the disease on to offspring. If both parents have the autosomal recessive condition, the chance of mutation in offspring increases to 100%. An individual will be considered a carrier if one mutant copy of the gene is inherited, and will not illustrate any symptoms. The disease affects both men and women equally, and overall, is a very uncommon inherited or acquired disorder.

Non-inheritance and other factors:

There are two types of prothrombin deficiencies that occur depending on the mutation:

Type I (true deficiency), includes a missense or nonsense mutation, essentially decreasing prothrombin production. This is associated with bleeding from birth. Here, plasma levels of prothrombin are typically less than 10% of normal levels.

Type II, known as dysprothrombinemia, includes a missense mutation at specific Xa factor cleavage sites and serine protease prothrombin regions. Type II deficiency creates a dysfunctional protein with decreased activity and usually normal or low-normal antigen levels. A vitamin K-dependent clotting factor is seldom seen as a contributor to inherited prothrombin deficiencies, but lack of Vitamin K decreases the synthesis of prothrombin in liver cells.

Acquired underlying causes of this condition include severe liver disease, warfarin overdose, platelet disorders, and disseminated intravascular coagulation (DIC).

It may also be a rare adverse effect to Rocephin.

Activated protein C (with protein S as a cofactor) degrades Factor Va and Factor VIIIa. Activated protein C resistance is the inability of protein C to cleave Factor Va and/or Factor VIIIa, which allows for longer duration of thrombin generation and may lead to a hypercoagulable state. This may be hereditary or acquired. The best known and most common hereditary form is Factor V Leiden. Acquired forms occur in the presence of elevated Factor VIII concentrations.

There are numerous different mutations which cause each type of haemophilia. Due to differences in changes to the genes involved, people with haemophilia often have some level of active clotting factor. Individuals with less than 1% active factor are classified as having severe haemophilia, those with 1-5% active factor have moderate haemophilia, and those with mild haemophilia have between 5-40% of normal levels of active clotting factor.

No cure currently exists; however, gene therapy has been proposed.

An estimated 64 percent of patients with venous thromboembolism may have activated protein C resistance.

Newborns are relatively vitamin K deficient for a variety of reasons. They have low vitamin K stores at birth, vitamin K passes the placenta poorly, the levels of vitamin K in breast milk are low and the gut flora has not yet been developed (vitamin K is normally produced by intestinal bacteria).

Haemophilia A occurs in approximately 1 in 5,000 males, while the incidence of haemophilia B is 1 in 30,000 in male population, of these, 85% have haemophilia A and 15% have hemophilia B.

The disease causes an increased risk of bleeding. The most common sites of bleeding are the umbilicus, mucous membranes, gastrointestinal tract, circumcision and venepunctures.

ZAP70 deficiency, or zeta-chain-associated protein 70 kD deficiency, is a rare autosomal recessive form of severe combined immunodeficiency (SCID).

It is associated with ZAP70.

In terms of the cause of protein S deficiency it can be in "inherited" via autosomal dominance.A mutation in the PROS1 gene triggers the condition. The cytogenetic location of the gene in question is chromosome 3, specifically 3q11.1 Protein S deficiency can also be "acquired" due to vitamin K deficiency, treatment with warfarin, liver disease, and acute thrombosis (antiphospholipid antibodies may also be a cause as well)

Haemophilia C is caused by a deficiency of coagulation factor XI and is distinguished from haemophilia A and B by the fact it does not lead to bleeding into the joints. Furthermore, it has autosomal recessive inheritance, since the gene for factor XI is located on chromosome 4 (near the prekallikrein gene); and it is not completely recessive, individuals who are heterozygous also show increased bleeding.

Many mutations exist, and the bleeding risk is not always influenced by the severity of the deficiency. Hemophilia C is developed on occasion in individuals with systemic lupus erythematosus, because of inhibitors to the FXI protein.

Protein S deficiency is a disorder associated with increased risk of venous thrombosis. Protein S, a vitamin K-dependent physiological anticoagulant, acts as a nonenzymatic cofactor to activate protein C in the degradation of factor Va and factor VIIIa. Decreased (antigen) levels or impaired function of protein S leads to decreased degradation of factor Va and factor VIIIa and an increased propensity to venous thrombosis. Protein S circulates in human plasma in two forms: approximately 60 percent is bound to complement component C4b β-chain while the remaining 40 percent is free, only free protein S has activated protein C cofactor activity

Overall, according to a study in British Columbia, approximately 2.3 children per 100,000 births (1 in 43,000) have some form of glycogen storage disease. In the United States, they are estimated to occur in 1 per 20,000–25,000 births. Dutch incidence rate is estimated to be 1 per 40,000 births.

The prevalence of vitamin K deficiency varies by geographic region. For infants in the United States, vitamin K deficiency without bleeding may occur in as many as 50% of infants younger than 5 days old, with the classic hemorrhagic disease occurring in 0.25-1.7% of infants. Therefore, the Committee on Nutrition of the American Academy of Pediatrics recommends that 0.5 to 1.0 mg Vitamin K be administered to all newborns shortly after birth.

Postmenopausal and elderly women in Thailand have high risk of Vitamin K deficiency, compared with the normal value of young, reproductive females.

Current dosage recommendations for Vitamin K may be too low. The deposition of calcium in soft tissues, including arterial walls, is quite common, especially in those suffering from atherosclerosis, suggesting that Vitamin K deficiency is more common than previously thought.

Because colonic bacteria synthesize a significant portion of the Vitamin K required for human needs, individuals with disruptions to or insufficient amounts of these bacteria can be at risk for Vitamin K deficiency. Newborns, as mentioned above, fit into this category, as their colons are frequently not adequately colonized in the first five to seven days of life. (Consumption of the mother's milk can undo this temporary problem.) Another at-risk population comprises those individuals on any sort of long-term antibiotic therapy, as this can diminish the population of normal gut flora.

Hyaluronidase deficiency (also known as "mucopolysaccharidosis type IX") is a condition caused by mutations in HYAL1, and characterized by multiple soft-tissue masses.

Nezelof syndrome (also known as Thymic dysplasia with normal immunoglobulins) is an autosomal recessive congenital immunodeficiency condition due to underdevelopment of the thymus. The defect is a type of purine nucleoside phosphorylase deficiency with inactive phosphorylase, this results in an accumulation of deoxy-GTP which inhibits ribonucleotide reductase. Ribonucleotide reductase catalyzes the formation of deoxyribonucleotides from ribonucleotides, thus, DNA replication is inhibited.

Hypoprothrombinemia is found to present itself as either inherited or acquired, and is a decrease in the synthesis of prothrombin. In the process of inheritance, it marks itself as an autosomal recessive disorder, meaning that both parents must be carriers of the defective gene in order for the disorder to be present in a child. Prothrombin is a glycoprotein that occurs in blood plasma and functions as a precursor to the enzyme, thrombin, which acts to convert fibrinogen into fibrin, therefore, fortifying clots. This clotting process is known as coagulation.

The mechanism specific to prothrombin (factor II) includes the proteolytically cleaving, breakdown of proteins into smaller polypeptides or amino acids, of this coagulation factor in order to form thrombin at the beginning of the cascade, leading to stemming of blood loss. A mutation in factor II would essentially lead to hypoprothrombinemia. The mutation is presented on chromosome 11.

Areas where the disease has been shown to present itself at include the liver, since the glycoprotein is stored in this area.

Acquired cases are results from an isolated factor II deficiency. Specific cases include:

1. Vitamin-K Deficiency: In the liver, vitamin K plays an important role in the synthesis of coagulation factor II. Body's capacity in the storage of vitamin K is typically very low. Vitamin K-dependent coagulation factors have a very short half-life, sometimes leading to a deficiency when a depletion of vitamin K occurs. The liver synthesizes inactive precursor proteins in the absence of vitamin K (liver disease). Vitamin K deficiency leads to impaired clotting of the blood and in some cases, causes internal bleeding without an associated injury.

2. Disseminated Intravascular Coagulation (DIC): Involving abnormal, excessive generation of thrombin and fibrin within the blood. Relative to hypoprothrombinemia, due to increased platelet aggregation and coagulation factor consumption involved in the process.

3. Anticoagulants: Warfarin Overdose: Used as a treatment for prevention of blood clots, however, like most drugs, side effects have been shown to increase risk of excessive bleeding by functioning in the disruption of hepatic synthesis of coagulation factors II, VII, IX, and X. Vitamin K is an antagonist to warfarin drug, reversing its activity, causing it to be less effective in the process of blood clotting. Warfarin intake has been shown to interfere with Vitamin-K metabolism.

Genetically speaking, Nezelof syndrome is autosomal recessive. the condition is thought to be a variation of severe combined immunodeficiency(SCID) However, the precise cause of Nezelof syndrome remains uncertain