Prevalence of joint hypermobility syndromes in pediatric postural orthostatic tachycardia syndrome

Introduction: Patients with postural orthostatic tachycardia syndrome (POTS) have been shown to exhibit comorbid joint hypermobility manifested as Ehlers-Danlos syndrome (EDS) or hypermobility spectrum disorder (HSD). The prevalence of EDS and HSD in POTS has been demonstrated in smaller studies combining adult and pediatric patients. We examined a large series of pediatric patients to determine their prevalence in children with POTS. Materials and methods: Patients 18 years old, or less, at initial evaluation at our clinic were included. POTS was diagnosed based on at least six months of frequent debilitating symptoms of orthostatic intolerance, plus a consistent heart rate increase of at least 40 beats per minute without orthostatic hypotension on standing test. Patients with a Beighton score of at least 5/9 plus other systemic findings suggestive of EDS were further evaluated in Connective Tissue Disorders clinics. Results: There were 362 patients meeting inclusion criteria, of which 82 patients had EDS (22.7%) and 141 patients had HSD (39.0%). Patients with EDS had an earlier median age at symptom onset (12.1 vs. 13.5 years, p=0.004) and longer median symptom duration (2.5 vs. 1.5 years, p=0.0008) compared to patients without hypermobility. Conclusions: Our evaluation of a large series of pediatric patients with POTS revealed that over one-fifth of patients had EDS and over one-third of patients had HSD. The awareness of the prevalence of comorbidities such as hypermobility disorders may help inform providers diagnosing and caring for these patients.