The impact of fibrodysplasia ossificans progressiva (FOP) on patients and their family members: results from an international burden of illness survey.

BACKGROUND: Fibrodysplasia ossificans progressiva (FOP) is an ultra-rare, genetic disorder of heterotopic ossification within soft, connective tissues resulting in limited joint function and severe disability. We present results from an international burden of illness survey (NCT04665323) assessing physical, quality of life (QoL), and economic impacts of FOP on patients and family members. METHODS: Patient associations in 15 countries invited their members to participate; individuals with FOP and their family members were eligible. The survey was available online, in 11 languages, from 18 January-30 April 2021. Participants responded to assessments measuring joint function, QoL, healthcare service and living adaptation utilization, out-of-pocket costs, employment, and travel. RESULTS: The survey received 463 responses (patients, n = 219; family members, n = 244). For patients, decreased joint function was associated with reduced QoL and greater reliance on living adaptations. Nearly half of primary caregivers experienced a mild to moderate impact on their health/psychological wellbeing. Most primary caregivers and patients (≥18 years) reported that FOP impacted their career decisions. CONCLUSIONS: Data from this survey will improve understanding of the impact of FOP on patients and family members, which is important for identifying unmet needs, optimizing care, and improving support for the FOP community.

Study of the calcium dynamics of the human alpha4beta2, alpha3beta4 and alpha1beta1gammadelta nicotinic acetylcholine receptors.

In this study three major subtypes of nicotinic acetylcholine receptors were characterized pharmacologically using the calcium influx through the ion channel as a robust functional assay system. Human alpha3beta4 receptors and alpha4beta2 receptors were cloned and stably expressed in HEK293 cells. [(125)I]epibatidine saturation binding yielded a B(max) of 4420+/-840 fmol/mg protein for the alpha4beta2 receptor ( n=4) and 518+/-15 fmol/mg protein for the alpha3beta4 receptor ( n=4). As a source for muscle type of nicotinic receptor, the TE671 cell line was used which expresses endogenously the human fetal alpha1beta1gammadelta subtype of nicotinic receptor. Stimulation of these nicotinic receptor subtypes in the different cell lines led to calcium transients that peaked 5-10 s after agonist application and declined thereafter. Eleven agonists were tested in this study and their efficacy and potency at the three nicotinic receptor subtypes were determined (epibatidine, ABT594, anatoxin, ABT418, nicotine, DMPP, cytisine, ABT089, choline, GTS21, AAR17779). This pharmacological characterization of agonist-induced elevation of intracellular free Ca(2+) revealed a distinct rank order of agonist potency for each receptor subtype. Epibatidine showed at all three subtypes the highest potency and was a full agonist. The agonist-elicited response could be blocked by co-incubation of different antagonists from which mecamylamine did not display a strong subtype specificity. These data illustrate that the assessment of calcium transients upon receptor stimulation is a powerful tool for rapid examination of the functional properties of nicotinic receptors.