About Multiple Epiphyseal Dysplasia

What Causes MED and How Is It Inherited?

Multiple epiphyseal dysplasia happens because of a mutation (change) in a gene in a person’s DNA. Genes give instructions for the way the body works. There are multiple genetic causes for MED. As there are many different causes, many different changes in a variety of genes can lead to MED. Sometimes a child is the first in the family with MED and other times it has been passed down through the generations. A geneticist and/or genetic counselor can help families understand how MED was likely inherited for any particular individual.

What Are the Characteristics of MED?

Multiple epiphyseal dysplasia (MED) is not recognizable at birth, and individuals may not show any symptoms until they are around 2-5 years old, sometimes even older.

Symptoms can include:

• Shorter stature (height less than expected for their family, but may still be in typical range)
• Joint pain, usually of hips, knees and/or ankles, after extended exercise
• Joint stiffness, first thing in the morning and/or after sitting a long time
• Difference in how they walk

How Is Multiple Epiphyseal Dysplasia Diagnosed?

MED is most often diagnosed in childhood by X-rays showing differences in the epiphyses throughout the skeleton, plus symptoms of joint pain.

Multiple epiphyseal dysplasia is not typically diagnosed by prenatal ultrasound. If there is a family history of MED, and the associated gene is known, then an amniocentesis or CVS (chorionic villus sampling) can check the fetus for it too. Science has not yet discovered all the genetic causes of MED though, so it isn’t possible to find the genetic cause for every family.

Musculoskeletal Problems Associated With MED

Because this is due to a difference in the genetic instructions, the epiphyses are different not just in one place, but throughout the body. For example, this is in contrast with a diagnosis called Legg-Calves-Perthes, which usually just affects an epiphysis in one hip.

In MED, ossification the epiphyses is delayed and when they do mineralize the structure is different. The epiphyses in the hip are often irregular and flattened as shown in the X-ray.

Degenerative joint disease is expected, typically in the weight-bearing joints (hips, knees, and/or ankles) of the lower limbs, but can also be seen in the shoulders. Joint replacement is sometimes needed in adulthood. This is a condition where environment plays a big role in the progression of disease, so joint preserving exercise like swimming is much preferred to repetitive pounding activities like long distance running on concrete.

Additionally, bow legs (genu varum), or knock-knees (genu valgum) can sometimes develop, as can flat feet (pes planus).

Health Issues Related to MED

Apart from problems in joints, no other system is affected.

What to Watch for With Multiple Epiphyseal Dysplasia

Joint pain, which could be fluctuating or episodic in childhood, develops more consistently in adolescence or early adulthood.

Treatment for MED may include:

• Talking about MED — both with your child and others — as a difference rather than a problem. Your attitude can help your child develop good self-esteem.
• Find ways to adapt and stay away from repetitive pounding activities for joint preservation. For example, avoid bounce-houses and trampolines as a family, so that your child will not be singled out by not joining in.
• Talk to the school about gym adaptations, with activities to tolerance.
• Taking hot baths (with moving water if possible) after a long day of activity to minimize joint pain/stiffness
• NSAIDS as needed for pain
• Weight management
• Surgery, including joint realignments in childhood, or replacements as needed in adulthood