Relationship and New Prospectives in Joint Hypermobility in Children with Autism Spectrum Disorder: Preliminary Data

Autism in the context of joint hypermobility, hypermobility spectrum disorders, and Ehlers-Danlos syndromes: A systematic review and prevalence meta-analyses

Increasing research suggests a link between autism spectrum disorders and joint hypermobility, hypermobility spectrum disorders, and Ehlers-Danlos syndromes. However, no study systematically examined the available literature about the relationship between these conditions. A systematic literature search was conducted to identify studies (a) examining the link between autism, joint hypermobility, hypermobility spectrum disorders or Ehlers-Danlos syndrome, and (b) reporting the frequency of autism spectrum disorders in people with joint hypermobility, hypermobility spectrum disorders or Ehlers-Danlos syndrome, or vice versa. Prevalence meta-analyses were performed. Twenty articles met the inclusion criteria. Twelve studies explored joint hypermobility/hypermobility spectrum disorders/Ehlers-Danlos syndrome in autistic people. Six explored autism spectrum disorders/autistic traits in people with hypermobility spectrum disorders/Ehlers-Danlos syndrome. Two studies examined autism spectrum disorders in relatives of patients with hypermobility spectrum disorders/Ehlers-Danlos syndrome, and two explored autistic traits and joint hypermobility in non-clinical samples. Out of 15 studies examining the association between autism spectrum disorders/autistic traits and joint hypermobility/hypermobility spectrum disorders/Ehlers-Danlos syndrome, 12 reported significant results. The overall prevalence of joint hypermobility in autistic individuals was 22.3%, but it was higher (31%) when only studies assessing joint hypermobility clinically (excluding self-reports) were considered. The overall prevalence of hypermobility spectrum disorders/Ehlers-Danlos syndrome in autistic samples was 27.9%, but 39% if hypermobility spectrum disorders/Ehlers-Danlos syndrome were assessed clinically. Despite the heterogeneity of studies, these results suggest an association between autism and joint hypermobility/hypermobility spectrum disorders/Ehlers-Danlos syndrome that should be confirmed in further research.Lay abstractIncreasing research suggests a link between autism spectrum disorders (ASD) and joint hypermobility (JH), hypermobility spectrum disorders (HSD), and Ehlers-Danlos syndromes (EDS). However, no study systematically examined the available literature about the relationship between these conditions. To fill this gap, we conducted a systematic literature search to identify studies: (a) examining the link between autism, JH, HSD, or EDS, and (b) reporting the frequency of ASD in people with JH, HSD, or EDS, or vice versa. Prevalence meta-analyses were performed. Twenty articles met the inclusion criteria. Twelve studies explored JH/HSD/EDS in autistic people. Six explored ASD/autistic traits in people with HSD/EDS. Two studies examined ASD in relatives of patients with HSD/EDS, and two explored autistic traits and JH in non-clinical samples. Out of 15 studies examining the association between ASD/autistic traits and JH/HSD/EDS, 12 reported significant results. The overall prevalence of JH in autistic individuals was 22.3%, but it was higher (31%) when only studies assessing JH clinically (excluding self-reports) were considered. The overall prevalence of HSD/EDS in autistic samples was 27.9%, but 39% if HSD/EDS were assessed clinically. Despite the heterogeneity of studies, these results suggest an association between autism and JH/HSD/EDS that should be confirmed in further research.

A New Method to Evaluate Joint Hypermobility in Paediatric Patients with Neurodevelopmental Disorders: A Preliminary Study

Background/Objectives: Neurodevelopmental disorders (NDDs) include a wide range of conditions that develop during the formation of the central nervous system, such as autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD). Tourette syndrome (TS) is another neurodevelopmental disorder characterised by motor and vocal tics, which often co-occurs with ASD and ADHD. This study explores the feasibility of assessing joint hypermobility in children with specific neurodevelopmental conditions by measuring both ankles' passive range of motion (pROM). Methods: This study involved children diagnosed with ASD, ADHD, and TS, aged 5 to 15 years, who were compared with a control group of healthy children. The Beighton and Brighton scores and the pROM of the left and right ankles were measured. Data were analysed using SPSS version 22.0 for Windows (IBM SPSS Statistics, Chicago, IL, USA). A total of 102 subjects participated in this study (72.52% male, with a mean age of 10.7 ± 2.2 years). The sample included 24 children with ASD, 27 with ADHD, 26 with TS, and 25 healthy controls. Results: The pROM of the right and left ankles showed a significant positive correlation with the Beighton and Brighton scores in children with NDDs (ASD, ADHD, and TS combined). A trend towards higher Beighton scores (≥6) was observed in the ADHD and TS groups, with significance found in the TS group (p = 0.013). The pROM of the right ankle was significantly higher in the ADHD (p = 0.021) and TS (p = 0.013) groups compared to the controls. Although the left ankle followed a similar trend in the TS group, the difference was not statistically significant (p = 0.066). Controlling for age, the diagnosis of ASD, ADHD, and TS does not appear to impact any of the variables examined. Conclusions: There is a trend towards a higher prevalence of individuals with elevated Beighton scores in the ADHD and TS groups, suggesting greater general flexibility or hypermobility in these patients. However, the pROM of the right ankle is significantly higher in the ADHD and TS groups, with solid evidence in the TS group. These findings were not observed in children with ASD. However, it is necessary to consider the measurements obtained in relation to the patients' age. Finally, given that the pROM of the ankles correlates with the Beighton and Brighton scores, it could be utilised for the initial screening, monitoring, and follow-up of JH in some children with NDDs. Further investigations are required.

Ligamentous laxity in children with achondroplasia: Prevalence, joint involvement, and implications for early intervention strategies

Achondroplasia (ACH), the most common form of skeletal dysplasia, is characterized by severe disproportionate short stature, rhizomelia, exaggerated lumbar lordosis, brachydactyly, macrocephaly with frontal bossing and midface hypoplasia. Ligamentous laxity has been reported as a striking feature of ACH, but its prevalence and characteristics have not been systematically evaluated yet. There is growing evidence that ligamentous laxity can be associated with chronic musculoskeletal problems and may affect motor development leading to abnormal developmental trajectories. This study aimed to assess the prevalence of ligamentous laxity in children with ACH through standardized tools, the Beighton scale and its modified version for preschool-age children. A total of 33 children (mean age 6.4 ± 3.2 years; age range 1-12.5 years) diagnosed with ACH by the demonstration of a pathogenic variant in the FGFR3 gene and 33 age- and sex-matched healthy controls were included in the study. Both ligamentous laxity assessment and neurological examinations were performed; medical history was also collected from caregivers. Children with ACH showed a 2 times higher risk of ligamentous laxity than the group without skeletal dysplasia (OR = 2.2; 95% CI = 1.0 to 4.7), with 55% of children meeting the diagnostic criteria for hypermobility. No significant difference in ligamentous laxity was observed between males and females. Joint involvement analysis revealed characteristic patterns, with knee hypermobility observed in 67% of patients, while rare was elbow hypermobility. Longitudinal assessments indicated a decreasing trend in ligamentous laxity scores over time, suggesting a potential decrease in hypermobility issues during adulthood. The findings of this study provide valuable insights into the prevalence and characteristics of ligamentous laxity in ACH. Implementation of standardized ligamentous laxity assessments might guide patients' follow-up and facilitate early interventions, helping to prevent pain and improve outcomes and quality of life for such patients. Further prospective studies are needed to explore the natural history of ligamentous laxity in ACH and investigate the potential impact of emerging pharmacological treatments upon hypermobility.