Real-World Impact of X-Linked Myotubular Myopathy (XLMTM) on Caregivers in the United Kingdom (UK), Germany, and Spain

OBJECTIVES: XLMTM is a rare, life-threatening congenital myopathy, and most individuals with XLMTM require constant lifelong care. The impact on caregivers of individuals with XLMTM has not been previously described in Europe. We conducted a survey to assess the health-related quality of life (HRQoL) of these caregivers and the direct and indirect financial impact of extensive supportive care in the UK, Germany, and Spain.

METHODS: A web-based survey was conducted in the UK (August 2021–October 2023), Germany (June 2021–October 2023), and Spain (June 2023–March 2024). Consenting caregivers of a male individual diagnosed with XLMTM who were residents of those respective countries and had sufficient responses were included. Survey questions evaluated demographics, physical characteristics and impact of the disease, caregiver HRQoL (as assessed using the EuroQol 5-dimension 5-level and visual analog scale) and disease-related costs. Caregiver disutility was defined as the difference between general population utility scores and caregiver utility scores. An ethics committee in each country approved the study.

RESULTS: There were a total of 14 eligible caregiver respondents from the UK (median [range] age: 44 [31–57], female: n=9), 8 from Germany (median age: 32 [19–57]; female: n=7), and 11 from Spain (median age: 40 [36–50]; female: n=7). Mean (SD) caregiver disutility in the UK, Germany, and Spain was −0.137 (0.251), −0.041 (0.070), and −0.081 (0.053), respectively. Among caregivers in all countries, the HRQoL domains most impacted were anxiety/depression, pain/discomfort and usual activities. Median (range) annual caregiver productivity loss in the UK, Germany, and Spain was £17,470 (£0–39,533), €24,915 (€13,137–79,728), and €29,113 (€1400–36,783), respectively.

CONCLUSIONS: Caregivers reported substantial financial constraints, productivity loss, out-of-pocket expenses, and poor HRQoL for both physical and mental health regardless of location. These real-world data highlight the need for improved support for caregivers, as well as targeted therapies for individuals with XLMTM.