What are the symptoms? The main features of MED may include: a waddling gait (a jerky motion when walking rather than a smooth movement of the lower limbs)pain in the joints and fatigue (tiredness) after exerciseprogressive worsening of pain and joint stiffness and deformityreduced height in adults. In general, intelligence of a person is not affected by MED. Adults with MED are likely to have early onset osteoarthritis, which may lead to the need for early joint replacement. There is a rare form of MED, rMED, that is inherited in a recessive manner due to a change in both copies of a pair of genes. It is characterised by joint pain, malformation of the hands, feet and knees and scoliosis. Stature is usually within the normal range prior to puberty. In adulthood, stature is only slightly diminished and is in the range of 150 to 180 cm. Limitation of ability to move around and carry out everyday tasks, is mild or absent. What are the causes? Mutations (DNA changes) in a number of genes are known to cause MED. About 35 per cent of affected individuals have a mutation of the COMP gene on chromosome 19 while about 15 per cent have mutations in other genes. However, in about 50 per cent, a mutation cannot be identified. How is it diagnosed? A diagnosis of MED will be made on the clinical symptoms a person displays and by assessment of X-rays showing the malformation of the ends of the long bones. Molecular testing (testing of DNA) may also be offered to look for mutations known to cause MED. How is it treated? Treatments are given to reduce the impact of the symptoms of MED an affected person may experience; there is no cure. Control of pain and the limitation of joint destruction that can lead to the development of osteoarthritis are important. A combination of analgesics (pain killing drugs) and physiotherapy including hydrotherapy (doing exercises in a warm water pool) is helpful in many. Referral to a pain specialist and a rheumatologist may also be needed. Weight control and avoiding exercise that causes repetitive strain on affected joints is beneficial. Consultation with an orthopaedic surgeon can determine if certain operations to correct problems with bone are needed. In some cases, total joint replacement may be required. Psychological support may be needed to support a person who is short in stature and finds it affects their mood. Occupational therapy and aids and equipment for the home may be necessary to carry out daily activities. Inheritance patterns and prenatal diagnosis Inheritance patternsAutosomal dominant or, rarely, an autosomal recessive form. Affected families should be referred to a genetics centre for information and support. Prenatal diagnosisThis is possible in the case of families affected by MED where the mutation responsible for the condition is known. Testing is by amniocentesis at 16 to 18 weeks or by chorionic villus sampling at ten to 12 weeks. Is there support? Information and support in the UK for multiple epiphyseal dysplasia is provided by the Restricted Growth Association (see entry Restricted Growth).