Two sisters, 34 and 44 years of age, with Morquio's syndrome are described.
The two patients were characterized by dwarfism, deformity of various bones and chondroitin sulfate in the urine.
Audiometry revealed bilateral sensorineural hearing loss with TTS showing Jerger Type 1 in the ears both cases, while their tympanograms showed type C in both cases. Stapedial reflex was absent in the elder sister because of a severe hearing defect.
It was confirmed that the hearing defect in MPS IV was sensorineural in type due to an inner ear disease.