Bleeding Disorders (Haemophilia and Von Willebrand Disease)
Published: 07 February 2024
Published: 07 February 2024
Bleeding disorders affect over 7,000 people in Australia (Haemophilia Foundation Australia 2023a).
The most common bleeding disorders, von Willebrand disease and haemophilia, appear to be similar but have several key differences.
Bleeding disorders are a group of chronic conditions that occur when proteins in the blood known as clotting factors are absent or dysfunctional (Doherty & Kelley 2023).
As a result, the blood can't clot normally when the person is injured, leading to excessive bleeding (Doherty & Kelley 2023).
For more information on the physiology of blood clots, see the Ausmed Article An Introduction to Blood Clots.
The three most common bleeding disorders are:
(Doherty & Kelley 2023)
Von Willebrand disease (VWD) is the most common bleeding disorder around the world, affecting people of all genders and racial backgrounds (Better Health Channel 2022a).
The disorder is caused by an absent or dysfunctional von Willebrand factor (VWF), which slows or impairs the blood clotting process. Consequently, bleeding takes longer to stop than in the average person (Better Health Channel 2022a).
There are three types of VWD:
(Better Health Channel 2022a; CDC 2023)
VWD is almost always an inherited disorder (CDC 2023).
Types 1, 2A, 2B, and 2M are autosomal dominant disorders, meaning that only one parent needs to pass on the mutated gene (i.e. VWD allele) in order for their child to inherit the condition. In other words, the child has a 50% chance of inheriting the disorder, depending on whether they inherit the affected parent’s normal gene or the VWD allele (CDC 2023).
If both parents have VWD, there is a 25% chance of the child inheriting both VWD alleles. In this case, the disorder will be more severe (CDC 2021).
Types 2N and 3, on the other hand, are autosomal recessive disorders, meaning that both parents need to pass on the VWD allele in order for their child to inherit the condition. Therefore, if only one parent has VWD, it’s not possible for the child to inherit the condition - but they might still be a carrier. If both parents have VWD, there’s a 25% chance of the child inheriting the condition (CDC 2023).
In rare cases, the VWF gene can spontaneously mutate, causing VWD even without a family history of the disorder (CDC 2023).
It’s also rare but possible for VWD to be acquired later in life. This is thought to be caused by an autoimmune reaction that destroys the body’s VWF, triggered by illness or certain medicines. This type of VWD is not genetic (CDC 2023).
In VWD, bleeding generally affects the mucous membranes (nose, mouth, uterus, vagina, stomach, and intestines) (Better Health Channel 2022a).
Some people with mild illness have no noticeable symptoms and may not even be aware that they have the disorder (Healthdirect 2020).
Symptomatic people might experience:
(CDC 2023; Healthdirect 2020; Doherty & Kelley 2023)
Milder cases of VWD may not be recognised until a major bleeding problem occurs and indicates that something is abnormal (e.g. after surgery or an injury) (Better Health Channel 2022a).
Diagnosis might take into account:
(Better Health Channel 2022a)
Routine blood tests may display normal results as VWF levels naturally due to factors such as stress, exercise, and hormones. Therefore, testing may need to be repeated (Better Health Channel 2022a).
VWF can’t be cured, but an interprofessional team will help to develop a treatment plan and assist the patient to live well with the disorder (Better Health Channel 2022a).
Treatment options depend on the individual and the severity of their illness but may include:
(Better Health Channel 2022a)
Those with mild illness may only require treatment when undergoing surgery or if injured (Better Health Channel 2022a).
Haemophilia is a bleeding disorder that occurs when there isn’t enough of either the VIII or IX clotting factor, meaning the blood can’t clot properly (Better Health Channel 2019a). There are two types of haemophilia:
(Better Health Channel 2022b; Haemophilia Foundation Australia 2023b)
Generally, those with less than 40% of the normal level of the clotting factor are considered to have haemophilia (Haemophilia Foundation Australia 2023b).
Most people with haemophilia are male, and severe disease in females is very rare (Haemophilia Foundation Australia 2023b).
Haemophilia is an X-linked recessive disorder, meaning the mutated gene is on the X chromosome. Males will receive the Y chromosome from their father and either one of their mother’s two X chromosomes. If the mother is a carrier of the mutated haemophilia gene, there is a 50% chance of the male child inheriting the mutation. As males only have one X chromosome, there is no other gene to cancel out the mutation if it is passed on (Centre For Genetics Education 2021).
As females have two X chromosomes, the second X chromosome will generally ‘cancel out’ the mutation (as the mutation is recessive) and therefore, most females who inherit the mutated gene are unaffected or only experience a mild reduction in the affected clotting factor. They will become carriers, however (Haemophilia Foundation Australia 2023c).
This X-linked recessive pattern causes haemophilia to be much more common in males - it affects about 1 in 6,000 to 10,000 males compared to less than 1 per 300,000 females (RCHM 2023).
In about one-third of cases, the gene mutation occurs spontaneously without any family history of the disorder (Haemophilia Foundation Australia 2023c).
Like VWD, it’s possible, but rare, for haemophilia to be acquired later in life (Better Health Channel 2022b).
Haemophilia is categorised as either mild, moderate, or severe, depending on the concentration of the affected clotting factor in the patient’s blood:
Note: The typical unaffected person has a concentration of between 50 and 150% factor VIII and factor IX in their blood (Better Health Channel 2022b).
Severity | Concentration of clotting factor | Characteristics |
---|---|---|
Mild | 5 to 40% |
|
Moderate | 1 to 5% |
|
Severe | Less than 1% |
|
(Adapted from Better Health Channel 2022b; RCHM 2023)
Unlike VWD, which predominantly affects the mucous membranes, haemophilia mainly causes internal bleeding into the joints and muscles. This can cause permanent damage over time, potentially leading to arthritis or chronic pain (Better Health Channel 2022b).
Other symptoms may include:
(Healthdirect 2023)
Signs of haemophilia in early infancy may include:
(Better Health Channel 2022b)
Haemophilia may be diagnosed prenatally, during infancy or later in life. Milder cases of haemophilia might not be diagnosed until the individual undergoes surgery or experiences trauma, as there is often enough of the clotting factor present for minor injuries to heal normally (Better Health Channel 2022b).
Diagnosis may involve:
(Better Health Channel 2022b)
Symptoms may be managed similarly to VWD, using treatment options such as:
(Better Health Channel 2022b)
Question 1 of 3
A woman who is a carrier of haemophilia and an unaffected man are expecting a child together. If their baby is male, how likely is he to inherit haemophilia?