Doctor Raises Awareness for Hypermobility Spectrum Disorder

Children may often appear double-jointed. Their flexibility, until the age of 5, can make it seem like they are made of rubber. They make rebounding from a fall, tumbling, and moving their bodies in unique ways look easy.

While they usually outgrow this resiliency by age 18 as joints mature and stabilize, for some children, joint hypermobility can be a lifelong problem. Joint hypermobility means that some or all of a person’s joints have an unusually large range of movement, and they are able to move their limbs into positions others find impossible.

Some people also refer to this as having loose joints or being double-jointed. Because children have high levels of joint hypermobility, it can be difficult to distinguish those with a normal physical trait from those with an underlying disorder.

Mekhla Varma, MD, a Stanford Medicine Children’s Health pediatrician at South Bascom Pediatrics and Stanford Medicine Children’s Health Pediatrics – Los Gatos locations, explained that hypermobility disorders were once identified mostly with Ehlers-Danlos syndromes (EDS) and Marfan syndrome, rare but serious connective tissue diseases that are inherited. Hypermobility spectrum disorder (HSD) is now classified as a separate syndrome, with a spectrum of symptoms and severity from asymptomatic to severe.

These heritable connective tissue disorders are caused by genetic changes that affect connective tissue. Some features are seen across all types of EDS, including joint hypermobility, skin hyperextensibility, and tissue fragility. The most common type of EDS is hypermobile EDS (hEDS).

“In 2017, stricter criteria were developed to diagnose hEDS, after the International Consortium on Ehlers-Danlos Syndromes (EDS) and Hypermobility Spectrum Disorders established new guidelines for the condition,” Dr. Varma explained.

“It was recognized that joint hypermobility is a continuum, and while not everyone meets criteria for hEDS, joint hypermobility can have severe impact on lives, whether it’s because of direct joint issues or because of other issues associated with joint hypermobility,” she said. “Hence, hypermobility spectrum disorder became a new diagnosis. The essential difference between HSD and hEDS lies in the stricter criteria for hEDS compared to the HSD.”

Connective tissue laxity not only affects joints but, more important, can cause other organs and body systems to not work properly, creating many problems. Since connective tissue is found throughout the body, it supports, protects, and gives structure to organs and systems, Dr. Varma said.

The core comorbid conditions that children present with are chronic pain, functional GI disorders, chronic fatigue, functional bladder disorders, dysautonomia, and anxiety, she added.

“HSD is fluid and keeps evolving, especially as children age, making it difficult to label kids in the different stages of evolution,” she said.

Dr. Varma has been advancing her knowledge of HSD for more than a decade and is raising awareness for HSD, as the combined prevalence of HSD and hEDS is between 1 in 600 and 1 in 900—and likely underdiagnosed.

“While working at a pediatric rheumatology clinic more than a decade ago, I had many patients who presented with nonspecific joint pain, and after autoimmune arthritis was ruled out, they were all classified in one big category of benign joint hypermobility syndrome. That’s when I started digging deeper into connective tissue disorders. We understand so much more now and continue to learn more.”

While joint instability may be obvious, some of the ways the condition affects the body are not readily noticeable, Dr. Varma noted. HSD can be associated with the following:

Stomach and digestive problems (reflux and slow stomach emptying)

Poor proprioception (the body’s ability to sense its position and movements in space)

Bladder and bowel problems

Autonomic dysfunction, including dizziness, fainting, light-headedness, difficulty regulating temperature

Easy bruising

Poor wound healing

Long-term (persistent) pain

Stretchy or soft skin

Chronic fatigue

Mast cell activation

Anxiety

It helps to have a team of doctors collaborating on a child’s HSD care, she said, and Stanford Medicine Children’s Health has an extensive network of specialists. “We treat the individual issues that arise related to HSD. As a generalist, I diagnose the condition, understand, and manage the issues, and refer to a specialist as needed.”

If parents suspect that their child might be hypermobile, Dr. Varma recommends talking to their pediatrician. “Some kids are hypermobile with no other issues and there is nothing that needs to be done,” she said, “but awareness is key.”

Dr. Varma is confident that as she and others continue to study hypermobility disorders, more information will be available.

For more information, visit The Ehlers-Danlos Society and Hypermobility Syndromes Association.