Ear symptoms in children with Fabry disease: data from the Fabry Outcome Survey

Background: Hearing loss and tinnitus are common symptoms in Fabry disease and increase in prevalence with age. This study aimed to provide an epidemiological description of hearing impairment and tinnitus in children with Fabry disease in the Fabry Outcome Survey (FOS), an international database to assess the natural history of Fabry disease and the efficacy of enzyme replacement therapy with agalsidase alfa. Methods: Signs and symptoms questionnaires were completed for 543 children with Fabry disease. Pure-tone audiograms were obtained from 101 children (53 girls, 48 boys). Results: On questioning, 33% of the children (n=179) reported subjective hearing impairment. However, when assessed by age-appropriate audiometry, only 19 of 101 patients (19%) had a persistent hearing loss at least one frequency. Of these, 14 had a high-frequency hearing loss, 4 a pan-frequency hearing loss, and 1 a pattern typical of noise-induced loss. Of the 101 children with audiometry, 44 complained of tinnitus. Only 2 children reported sudden hearing loss, which was not verified by audiometry. Children with tinnitus had greater disease severity scores. Conclusions: Hearing loss is a well-known clinical manifestation in patients with Fabry disease. It was reported in significant numbers of children in the FOS signs and symptoms questionnaire, but confirmed in only 19% by formal audiometry. The subjective hearing impairment may have been due to middle-ear effusions in many cases. Tinnitus is a well-recognized symptom in Fabry disease and can present in childhood. The presence of tinnitus correlated with overall disease severity.