Subjective and Objective Assessment of Hand Function in Mucopolysaccharidosis IVa Patients

Morquio A is classically described as a skeletal dysplasia, but the impact of the abnormalities on the upper limb has not been described.

The aim of our study is to assess the level of subjective and objective functions of the hand and upper limb in Morquio A patients in order to advance understanding as this may change future management for this complex group of patients.

We have evaluated a series of ten patients with Morquio syndrome who are currently part of the enzyme replacement therapy trials in our unit. To establish functional levels, we developed a questionnaire based on the principles of the World Health Organization International Classification of Functioning, Disability and Health (WHO ICF). Furthermore, we measured patients' grip function and range of motion.

All patients showed hypermobility and limited control of the wrist. Their grip strength was reduced and they showed higher difficulty levels for activities involving strength. It is feasible that the wrist abnormalities may be the major cause of functional loss for Morquio patients.

Our findings suggest the wrist itself represents an area that we should focus on to be able to improve the patients' functional abilities and hence their level of independence on day-to-day basis.