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.

Survey on the worldwide availability and affordability of antiseizure medications: Report of the ILAE Task Force on Access to Treatment

Health systems worldwide are challenged in the provision of basic medical services and access to treatments for chronic conditions. Epilepsy, the most common severe chronic neurological disorder, does not receive sufficient attention despite being officially declared a public health priority by the World Health Organization. More than 80% of people with epilepsy live in middle- and low-income countries (MICs and LICs, respectively), where most of the population lacks reliable access to antiseizure medications (ASMs), contributing significantly to the large epilepsy treatment gap in these regions. The International League Against Epilepsy (ILAE) Task Force on Access to Treatment administered a global survey to report on the current access to ASMs worldwide. The survey was developed and distributed online through the ILAE and International Bureau of Epilepsy (IBE) secretariats to the chapter representatives. The survey was completed by one representative per country. Response rate was 73.2% (101 countries of the 138 represented in ILAE and/or IBE organizations). Availability and access of ASMs, including distribution problems and costs, reimbursement procedures, general barriers to access to care, and presence of projects targeted toward improving care access, were studied, and descriptive statistics on available responses were performed. Among the 15 first-generation ASMs surveyed, carbamazepine was reported as the most widely available globally. At least one first-generation ASM is widely available in most countries, but their number differs dramatically across income levels. Second- and third-generation ASMs are even more limited in MICs and LICs. Additionally, average retail prices for ASMs were not significantly different across countries despite the differences in per capita income from high-income countries to LICs. This survey provides a worrisome picture of availability and accessibility of ASMs across the world, with wide disparities according to socioeconomic status. Recommendations for direct action on improving access to care will be discussed.

Fatal Status Epilepticus in Dravet Syndrome

Dravet Syndrome (DS) is burdened by high epilepsy-related premature mortality due to status epilepticus (SE). We surveyed centres within Europe through the Dravet Italia Onlus and EpiCARE network (European Reference Network for Rare and Complex Epilepsies). We collated responses on seven DS SCN1A+ patients who died following refractory SE (mean age 6.9 year, range 1.3–23.4 year); six were on valproate, clobazam, and stiripentol. All patients had previous SE. Fatal SE was always triggered by fever: either respiratory infection or one case of hexavalent vaccination. SE lasted between 80 min and 9 h and all patients received IV benzodiazepines. Four patients died during or within hours of SE; in three patients, SE was followed by coma with death occurring after 13–60 days. Our survey supports the hypothesis that unresponsive fever is a core characteristic feature of acute encephalopathy. We highlight the need for management protocols for prolonged seizures and SE in DS.

Defective proteasome biogenesis into skin fibroblasts isolated from Rett syndrome subjects with MeCP2 non-sense mutations

Rett Syndrome (RTT) is a rare X-linked neurodevelopmental disorder which affects about 1: 10000 live births. In >95% of subjects RTT is caused by a mutation in Methyl-CpG binding protein-2 (MECP2) gene, which encodes for a transcription regulator with pleiotropic genetic/epigenetic activities. The molecular mechanisms underscoring the phenotypic alteration of RTT are largely unknown and this has impaired the development of therapeutic approaches to alleviate signs and symptoms during disease progression. A defective proteasome biogenesis into two skin primary fibroblasts isolated from RTT subjects harbouring non-sense (early-truncating) MeCP2 mutations (i.e., R190fs and R255X) is herewith reported. Proteasome is the proteolytic machinery of Ubiquitin Proteasome System (UPS), a pathway of overwhelming relevance for post-mitotic cells metabolism. Molecular, transcription and proteomic analyses indicate that MeCP2 mutations down-regulate the expression of one proteasome subunit, α7, and of two chaperones, PAC1 and PAC2, which bind each other in the earliest step of proteasome biogenesis. Furthermore, this molecular alteration recapitulates in neuron-like SH-SY5Y cells upon silencing of MeCP2 expression, envisaging a general significance of this transcription regulator in proteasome biogenesis.