Translation of quality of life scale for pediatric patients with Fabry disease in Japan

Introduction: Fabry disease is a rare, X-linked lysosomal storage disorder that begins in childhood with a wide variety of symptoms, including neuropathic pain, gastrointestinal abnormalities, and skin abnormalities. Despite the substantial impact of these symptoms on children's quality of life (QOL), systematic QOL analysis of Japanese pediatric Fabry disease patients has been limited. Therefore, to evaluate the QOL of Japanese pediatric Fabry disease patients using standardized and disease-specific scales, we used the Fabry-specific Pediatric Health and Pain Questionnaire (FPHPQ), which was developed by the Fabry Outcome Survey. Methods: The FPHPQ was translated in accordance with the Principles of Good Practice for the Translation and Cultural Adaptation Process for Patient-Reported Outcomes. A back-translated version was reviewed twice by the original lead author of FPHPQ to confirm the conceptual equivalence. The questionnaire was then validated by cognitive debriefing, and distributed to pediatric Fabry disease patients in Japan. Results: Questionnaire responses were obtained from eight patients. The mean scores on the FPHPQ were 11.0 (+/- 11.43) for heat-associated pain, 5.5 (+/- 4.60) for cold-associated pain, and 14.8 (+/- 5.97) for abdominal pain and fatigue. In addition, heat-associated pain negatively correlated with physical well-being, whereas cold-associated pain positively correlated with good friendships. Conclusion: We established the Japanese version of the FPHPQ to assess the QOL of pediatric Fabry disease patients. The internal consistency and partial criterion-related validity of the Japanese version were confirmed. Analysis of a larger number of patients should be performed in the future to further validate the outcomes of this study.