Ehlers-Danlos Syndrome and Its Comorbidities as a Co-Occurring Health Issue in Autistic People

Ehlers-Danlos Syndrome (EDS) occurs in as many as 8% of autistic individuals with even a higher percentage that may have hypermobility spectrum disorders (HSD) (Cederlof et al., 2016, Kindgren et al., 2021). This estimate is low since EDS is more commonly diagnosed in females (Castori, 2012), who are generally undercounted in assessing characteristics of autism. There are currently 13 accepted subtypes of EDS (Miller & Grosel 2017), with genetic testing for 12 of the subtypes, but not for the estimated 90% with Hypermobile EDS (hEDS). Occupational and physical therapists (OTs and PTs) are often the first to note signs of EDS that include lax joints or low tone, both commonly noted in documentation of clients diagnosed with autism. Autistic children frequently have sensory processing differences, and EDS may compound the effects upon the sensory system, including a general hyposensitivity to proprioceptive input (feedback from muscles and joints) and vestibular issues, such as dizziness (Levine et al., 2021).

Double jointed young boy with hypermobility of the elbow leans forward with weight on his arm

EDS and HSD include known risk factors for joint pain (Baeza-Velasco et al,. 2018), subluxation (Shirley et al., 2012), full dislocation (Dabbas et al., 2008), immune system conditions (Brock et al., 2021), gastrointestinal disorders (Beckers et al., 2017), and other conditions that may cause severe pain. This may contribute to delays in communication and other skill development in young autistic individuals. Up to 89% of people with hEDS or HSD develop a Mast Cell Activation Disorder (MCAD) (Monaco et al., 2022). Symptoms related to MCADs include a lack of mental clarity that impacts learning new information, word-finding difficulty, cognitive processing issues, and difficulties regulating emotions. A person diagnosed with autism who also has MCAD may experience increased early learning difficulties, self-injurious behavior, and perceived aggression that are frequently associated with autistic individuals with high support needs (Theoharides et al., 2019).

Besides these potential diagnoses, people with EDS have a higher incidence of dysautonomia, particularly Postural Orthostatic Tachycardia Syndrome (POTS) (Mathias et al., 2021), autoimmune disorders (Celiac disease, lupus, multiple sclerosis, etc.) (Rodgers et al., 2017), Primary Immunodeficiency Disorders, such as CVID, (Brock et al., 2021), immunoglobulin deficiency disorders, and gastrointestinal dysmotility, sometimes leading to diagnoses of gastroparesis (Alomari et al., 2020). Since collagen and other connective tissue are part of the foundation of the neurological tissue, differences in the connective tissue in EDS may be why so many with EDS are also neurodivergent (Castori & Voermans 2014).

EDS, HSD, and MCAD may be difficult to diagnose, further impacting the prevalence of the disorder. Currently, genetic testing is available for all 13 types of EDS except for Hypermobile EDS (hEDS) (Forghani, 2019). While initial testing for MCAD looks for high serum tryptase counts, this is only a valid test if the person has Mastocytosis or Hereditary Alpha Tryptasaemia (Wu & Lyons 2022). Research indicates that 10% of mastocytosis pediatric patients are autistic (Theoharides, 2009). Research is still in process for the prevalence of HαT in autism, but it is widely-accepted there is an incidence of 6% of people having the mutated gene for this MCAD. Recent research, however, indicates that Mast Cell Activation Syndrome (MCAS) may have an incidence of 17% (Vacheron et al., 2021), with most people only experiencing mild symptoms, such as dermatological or gastrointestinal sensitivities. Underdiagnosis may also be due to the testing process. Testing usually includes a 24-hour urine collection. If the urine is not frozen immediately, typical room temperatures break down the histamine byproducts and the test is likely to return a false negative (Valent et al., 2020). Further, only about 16% of people with MCAS have high serum tryptase (Afrin et al., 2017). Tryptase is suspected to act much like a meat tenderizer as noted by Dr. Afrin (2016) and is thought to be related to the joint issues common in EDS, possibly even an underlying cause since mast cells break down collagen. High histamine can result in what appears to be an extreme allergic reaction however, even if IgE (Immunoglobulin E) allergy testing comes back negative (Theoharides et al., 2019). While there is no research data available at this time, anecdotally people with MCAD report that their joint hypermobility has decreased, to the extent that some have been able to return to beloved activities that place a great deal of pressure upon their joints (Hell’s Bells and Mast Cells, 2022).

MCADs can present very differently in different people (Afrin et al., 2016). Mast cells initially develop in the bone marrow and are distributed by the vascular system and mature in various areas of the body. Depending upon what organ or biochemical system is affected by abnormal mast cells people can experience a very diverse variety of symptoms, everything from GI sensitivities to food (Weinstock et al., 2021), severe allergic reactions, and unusual presentations of a variety of diseases or disorders that frequently do not respond to the usual treatment. Mast cells are found in the brain, with higher numbers in the amygdala and the cerebellum, both of which have been documented to be atypical in either form or activity in autistic individuals (Hendrikson et al., 2017).

Recognizing that EDS, HSD, and MCADs may be underdiagnosed, it should be considered when working with autistic children and adults due to its potential impact on behaviors, communication, and executive functioning. As previously noted, OTs and PTs may be the first medical professionals to recognize the signs of EDS. Due to the complexity of issues autistic children with EDS may face, occupational therapy plays a key role in improving patient outcomes. OTs have a unique ability to design interventions to address the known symptoms of these co-occurring disorders to help clients improve participation and functioning and manage their symptoms. EDS and related disorders impact more than physical and can cause difficulties in social, emotional, and mental health and well-being (Levine et al., 2021), which may be more pronounced in autistic individuals. Occupational therapists address symptoms see in both EDS and autism including modifying the environment, training in the use of adaptive equipment to improve independence, energy conservation, and improving sleep hygiene, to name a few. Occupational therapists address physical, sensory, emotional, and social areas to help person improve overall participation and engagement in daily activities (Levine et al., 2021). Further, occupational therapy is recognized as an effective intervention in up to 70% of individuals with EDS (Song et al., 2020).

Occupational therapists should be aware of other comorbidities that may impact a person, such as pain, that the person may not be able to adequately identify or communicate. They should be trained in recognizing pediatric pain symptoms even when pain is not reported. They should also work to address motor performance to support and protect joints and prevent subluxation. Further, OTs and other therapists need to be considerate of the impact of these disorders on executive functioning and help design interventions to support executive functioning through cognitive training and environmental supports. In addition, OTs need to be mindful of the potential GI implications that may impact feeding and eating, overall nutrition, and energy levels to participation in daily activities. OTs address the needs of the whole child to ensure symptoms are managed in a manner that promotes participation in daily activities, leading to increased participation and increased sense of well-being.

If you suspect you or someone in your care may meet the criteria for Ehlers-Danlos Syndrome, please refer to the Beighton Criteria for Joint Hypermobility. If you further suspect the presence of an undiagnosed Mast Cell Activation Disorder, you can go through a checklist of common symptoms at the Bonn Validated Mast Cell Questionnaire.

Tara J. Marshall, BA, SLPA, is an Autistic adult with hEDS and a suspected Mast Cell Activation Disorder working as a Speech Language Pathology Assistant. Aimee Piller, PhD, OTR/L, BCP, FAOTA, is a pediatric occupational therapist and owner of Piller Child Development, LLC who specializes in sensory processing disorders.


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