What is hypermobility?
Hypermobility joints are joints that move further than the usual range, taking into account someone’s age, gender and ethnic background. Many individuals have one or several Hypermobility joints and factors such as bone shape and muscle tone can increase the range of movement of a joint. For some this is not associated with any difficulties. The diagnosis of EDS-HT is made when there are other problems associated with hypermobility.
What are the differences between joint hypermobility syndrome & EDS hypermobility type(EDS-HT)?
There has been considerable debate about whether JHS is a distinct and separate condition from Hypermobility EDS (EDS-HT). Since people with hypermobility can have a wide range of features it may be that there is a group of several similar conditions. It is thought that EDS-HT should be diagnosed when there are other symptoms present, such as Gastrointestinal, Autonomic and Skin related issues.
JHS is often used to describe hypermobility, chronic pain and chronic fatigue. This is not a universal opinion and is still an area of debate amongst medical professionals. There are currently no tests to separate JHS and Hypermobility EDS. Other names including EDS type III and Benign Joint Hypermobility syndrome have previously been used.
What are the Ehlers-Danlos syndromes (EDS)?
EDS is the term given to a whole collection of inherited conditions that fit into a larger group known as hereditary disorders of connective tissue. Connective tissues provide support in skin, tendons, ligaments and bones. There are several different, distinct types of EDS, but they have some features in common. These can include joint hypermobility (increased mobility of joints), stretchy skin and tissue fragility.
What are the main symptoms and signs of EDS-HT?
There can be considerable variability in the condition, even within the same family. Some people have joint hypermobility but do not have any other symptoms. Others can be more severely affected. Individuals with EDS-HT may have the following features:
- Joint hypermobility with the joints having a wider range of movement than usual.
- Loose, unstable joints that can lead to dislocations and subluxations.
- Joint pain and fatigue.
- Easy bruising.
- Gastrointestinal dysfunction.
- POTS (postural orthostatic tachycardia syndrome) causing fast heart rate, dizziness and fainting.
- Mitral valve prolapse, a heart valve abnormality which is usually only mild in EDS-HT.
- Uterine, rectal or bladder prolapse.
- Urinary dysfunction.
- Varicose veins.
What causes Hypermobility Ehlers-Danlos syndrome?
The exact cause(s) of EDS-HT is unknown. The features of HEDS suggest that there is a problem with connective tissues and possibly collagen. The condition appears to be inherited which suggests that there is a genetic cause. It is likely that there is an alteration in a gene, or several genes, containing the instructions for making connective tissue. This results in the connective tissue being less effective.
Is there a test for Hypermobility Ehlers-Danlos syndrome?
Currently the diagnosis of HEDS must be made on clinical features. There are no laboratory tests available to confirm the diagnosis.
How is Ehlers-Danlos syndrome inherited?
Our bodies are made up of millions of cells and inside almost every cell is a complete set of our genetic material. Genes are the unique instructions that make us each individual. There are many thousands of genes, each carrying a different instruction. We have two copies of each gene. One copy of each pair is inherited from our mother, in the egg, and the other from our father, in the sperm.
We have not yet been able to identify a gene that causes EDS-HTand it is possible that there may be several different genes involved. In fact EDS-HT may be a group of conditions and there could be various patterns of inheritance. In some families EDS-HT appears to follow a pattern called autosomal dominant inheritance. This means that someone with the condition has an alteration in one copy of a particular gene. Autosomal means it can affect and be passed on by both males and females. Symptoms can be very variable even within a family, with some family members being mildly affected and others having more severe problems.
When someone with this condition has children they will pass on one copy of the gene associated with EDS-HT to their child, either the altered or unaltered copy. Therefore, in each pregnancy there is a 50% (1 in 2) chance of a child inheriting the altered copy of the gene and having EDS-HT. Equally there is a 50% (1 in 2) chance of a child getting the unaltered copy of the gene and not inheriting the condition.
The gene alteration can happen for the first time in an individual, so there may be no previously affected family members. However this pattern of inheritance may not apply to all families, as the exact cause of EDS-HT is still unknown.
How can family members find out if this is relevant to them?
If family members would like further information about the implications for them, they should talk to their GP about the possibility of being referred to their local genetics service.
What management is recommended for people with Ehlers-Danlos syndrome hypermobility type?
- Regular gentle exercise, such as walking, cycling or swimming is encouraged to keep joints mobilised and to build up muscle tone around the joints to help stabilise them. Pilates can be very beneficial in helping maintain core stability and to develop good posture. It is particularly important to look after Hypermobility joints to help prevent injury. Contact sports increase the risk of injury and should be avoided. A physiotherapist can help you to develop appropriate exercises which can be carried out at home and give advice on other suitable activities.
- Maintaining a healthy weight by sensible eating and appropriate exercise will help to avoid additional stress on the joints
- Appropriate follow up is dependant on individual needs. Some people may benefit from referral to medical specialities such as: pain management, rheumatology, physiotherapy or occupational therapy.
- Individuals with EDS-HT may require an echocardiogram (ultrasound scan) of their heart to check the heart valves.
Are there any recommendations for women with Hypermobility Ehlers-Danlos syndrome who are considering a pregnancy?
HEDS is not usually associated with serious complications in pregnancy. We would suggest that women with EDS-HT inform their obstetrician (a doctor who specialises in the care of pregnant women) of the diagnosis.
There are a few points to consider for pregnant women with EDS-HT. Joint hypermobility tends to increase during pregnancy, due to the female hormones produced, and this may result in further instability and joint pain. There may be an increased chance of early rupture of the membranes (waters breaking), a rapid labour, or the baby being a breech presentation (feet/bottom first at delivery). Postnatal exercises to strengthen the pelvic floor are particularly important for women with EDS-HT.