Comprehensive Analysis of Hearing Function in Morquio A Syndrome: Implications for Diagnosis and Management

Abstract

Morquio A syndrome (Mucopolysaccharidosis IVA or MPS IVA) is a rare lysosomal storage disorder characterized by systemic skeletal dysplasia and progressive multi organ involvement. Its effects on hearing function are a common, yet under characterized, clinical manifestation of this disorder. Previous studies have noted the presence of mixed, conductive, and sensorineural hearing loss in patients with MPS IVA, but few have systematically examined auditory function using comprehensive behavioral and objective measures. This thesis investigates the auditory phenotype of individuals with Morquio A using the largest cohort assembled to date, with data collected through the Nemours Skeletal Dysplasia Lab. Auditory assessments included pure-tone thresholds (PTA), speech-recognition threshold (SRT), speech perception in quiet and noise (SIQ and SIN), tympanometry, otoacoustic emissions (DPOAEs), auditory brainstem responses (ABRs), and cortical auditory evoked potentials (CAEPs). These measures were used to determine the prevalence, type, and severity of hearing loss and to explore potential correlations with age, MPS IVA disease severity, and auditory system involvement. We found that the prevalence of hearing loss in this study population was 50.88% with a higher prevalence of sensorineural hearing loss over mixed and conductive types. There were no significant correlations found between hearing loss severity and disease severity or age at diagnosis. These findings suggest that hearing loss in MPS IVA patients may be affected by peripheral and central auditory system dysfunction. Due to the complex characterization of hearing loss in patients with MPS IVA, routine and comprehensive auditory evaluations are critical for early intervention and mitigation of its impact on communication and quality of life.