Hearing loss is a common but under-recognised complication of the rare disease MPS (mucopolysaccharidoses, a group of inherited conditions caused by enzyme deficiencies).
It often starts in childhood and can have a deep impact on quality of life.
Now an expert team led by consultant ear, nose and throat (ENT) surgeon Mr Chaitanya Gadepalli at Northern Care Alliance’s ENT department and Dr Eamon McCarron from the specialist metabolic unit have shed new light on the complication with the largest study yet, using data from more than 120 patients aged 16 and over who attend the unit at Salford Royal Hospital.
The retrospective study, supported by the research delivery team, showed that two thirds of patients whose hearing had been tested recently had hearing loss. This was mainly sensorineural hearing loss, which happens when the sensitive, hair-like cells within the cochlea (inner ear) or the hearing nerve become damaged.
Adult plateau
Lead author Dr Eamon McCarron explained: “Advances in treatment – including enzyme replacement therapy and stem cell transplantation – alongside improved supportive care, have substantially increased survival in people with MPS. That means more are now reaching adulthood but hearing loss profoundly affects communication and independence and can lead to social isolation and poorer quality of life.
“Our study found that adults with MPS type II and short-stature MPS IV are more severely affected. It also suggested that hearing loss is stable once its established, suggesting a plateau in adulthood.
“Current treatments don’t seem to make a difference to hearing loss – although they can help with respiratory function and mobility – so we recommend early testing, the use of appropriate hearing aids and lifelong checks on hearing.
“We would also like to see future research support the development of therapies capable of effectively targeting inner-ear pathology.”
The paper has been published in Molecular Genetics & Metabolism. Eamon McCarron, Karolina Stepien, Neil Summerfield, Reena Sharma, Ana Jovanovic, Nicole Gossan, Emma Burkitt-Wright, Chaitanya Gadepalli: Natural history of hearing loss in adults with mucopolysaccharidoses across phenotype and genotype.