P033 The intriguing association between fibromyalgia, hypermobility and neurodivergence: a pilot study

Abstract

Abstract Background/Aims Fibromyalgia (FM) is a common disorder with an estimated UK prevalence of 4%. An association with hypermobility spectrum disorder (HSD) has been recognised for several years and is increasingly recognised as a common precedent to chronic pain and FM. It has been recently suggested that these patients may have a higher rate of autistic spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD) or other neurodivergent conditions than the general population. This is supported by the observation that neurodivergence is strongly associated with chronic pain and disability. Methods We sought to assess the prevalence of ASD/ADHD among all first- and second-degree relatives of index patients who had presented to secondary care with the combination of FM, HSD and either ASD or ADHD. Eight consecutive index cases with this combination agreed to research their relatives and prepare a detailed family tree listing all family members, identified only by age and gender. They were asked to record the presence of all confirmed diagnoses of FM, HSD and ASD/ADHD among their first- and second-degree relatives. We then calculated the prevalence of each of these conditions among the close blood relatives of our index cases and compared this to the prevalence derived from a control group of index cases with osteoarthritis. Results Our eight index cases (seven female) had a mean age of 38 years. They identified 80 relatives, among whom 31 (39%) had a diagnosis of ASD/ADHD, compared to a prevalence of 2.8% in the relatives of our control group (p < 0.01). The prevalence of HSD among the relatives was 30% (vs 8% in controls) and the prevalence of FM was 18% (vs 3% in controls). There was significant overlap, with the prevalence of HSD and FM among relatives with ASD/ADHD being recorded as 50% and 30% respectively. 62% of the relatives were female. Conclusion Neurodivergent conditions are present from birth and therefore predate the onset of both HSD and FM. This pilot study confirmed that patients with the combination of FM and HSD have a much higher prevalence of neurodivergence than the general population, and that their close relatives also exhibit this association. Females are disproportionately over-represented in contrast to the distribution of neurodivergent conditions in the community, where males predominate. We noted that females with FM and HSD were more likely to have ASD, while males tended to carry a diagnosis of ADHD. One recent study suggested gene clustering among people with neurodivergence and those with FM / HSD. However, the reasons for, and mechanism of, this association remain to be defined. Much more work is needed to assess the evolution of pain among people with neurodivergent conditions if we are to learn how to intervene effectively. Disclosure T.B. Yearoo: None. C. Kelly: None.