Hypermobile Ehlers-Danlos syndrome (hEDS), which used to be known as the hypermobility type or type 3, is thought to be the most common genetic connective tissue disorder.
There is no up-to-date research to tell us exactly how frequently it occurs. It can be inherited from a parent with the same faulty gene, alternatively someone can be born with a new mutation so that the condition is occurring in their family for the first time.
Recently some changes were made to the way hypermobile Ehlers-Danlos syndrome is diagnosed. There is no test for hEDS, so diagnosis involves looking for joint hypermobility, signs of faulty connective tissue throughout the body (e.g. skin features, hernias, prolapses), a family history of the condition, and musculoskeletal problems (e.g. long-term pain, dislocations). There are many associated symptoms and disorders which don’t form part of the formal criteria, and which do not directly result from joint hypermobility, for instance orthostatic tachycardia, digestive disorders, pelvic and bladder dysfunction, and anxiety disorders. These are often more detrimental to quality of life than the joint symptoms.
Many people do not fully meet the new diagnostic criteria for hEDS but their hypermobility still causes problems for them. They may experience pain and dislocations, have a poor sense of where their joints are without looking, be prone to injury, have curvature of the spine, and degenerative joint and bone disease. These people may also have many of the non-musculoskeletal disorders associated with hEDS, but they do not quite ‘qualify’ for hEDS. After other possible conditions are excluded, a diagnosis of generalised hypermobility spectrum disorder may be made here.
Joint hypermobility with its possible complications is now classified using the idea of a spectrum. At one end is simple hypermobility which causes no symptoms, is not a disease and is a trait, like height. At the other end of our spectrum is hEDS, and in between falls a range of hypermobility-related conditions called hypermobility spectrum disorders (HSD).
Four subtypes of HSD are distinguished according to which joints are involved, whether the hypermobility is generalised throughout the whole body, and whether other musculoskeletal problems are present. It is also possible to have been hypermobile in the past and to have gradually become stiffer with age, but still have the musculosketal issues associated with that historical hypermobility.
HSD are likely to be common. Someone with HSD can be just as symptomatic, more so even, than someone with hEDS. Management advice for both hEDS and HSD is the same.
What are the differences between Joint Hypermobility Syndrome & Hypermobile EDS?
There has been considerable debate about whether JHS is a distinct and separate condition from Hypermobile EDS. 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 Hypermobile EDS 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 Hypermobile 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 Hypermobile EDS?
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 hEDS may have the following features:
Joint hypermobility with the joints having a wider range of movement than usual.
What causes Hypermobile EDS?
The exact cause(s) of hEDS 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 Hypermobile EDS?
Currently the diagnosis of hEDS must be made on clinical features. There are no laboratory tests available to confirm the diagnosis.
How is Hypermobile EDS 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 hEDS and it is possible that there may be several different genes involved. In fact hEDS may be a group of conditions and there could be various patterns of inheritance. In some families hEDS 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 hEDS 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 hEDS. 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 hEDS 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 Hypermobile EDS?
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 hypermobile 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 hEDS may require an echocardiogram (ultrasound scan) of their heart to check the heart valves.
Are there any recommendations for women with Hypermobile EDS who are considering a pregnancy?
HEDS is not usually associated with serious complications in pregnancy. We would suggest that women with hEDS 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 hEDS. 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 hEDS.
Please note: The above information cannot and should not replace advice from the patient's healthcare professional(s). Any person who experiences symptoms or feels that something may be wrong should seek individual, professional help for evaluation and/or treatment. This information is for guidance only and is not intended to provide individual medical advice.