By late teens and adulthood, the ribs are nearly horizontal and the sagittal diameter of the chest is greater than average. As a result, respiratory expansion becomes considerably impaired. Moreover, frequent upper and lower respiratory tract infections may occur due to the malformation of the rib cage.
Over half of people with Morquio syndrome develop narrowing of their trachea in the second decade of life. This can lead to life-threatening complications, especially during anesthesia. Therefore, imaging of the airway is recommended towards the end of the first decade as well as prior to any surgery thereafter. Treatment with surgery to reconstruct the trachea can be necessary in severe cases.
Lung function tests and sleep studies are frequently used to diagnose breathing problems in skeletal dysplasias. Regular visits with a pulmonologist is recommended. In the setting of prolonged severe breathing difficulties, some patients/families may choose invasive respiratory support with a tracheostomy and long-term mechanical ventilation.
Cardiac complications may occur, including cardiomyopathy, valvular disease or a late onset of aortic regurgitation. Cardiac anomalies are predominately left sided. Severe cases have resulted in death before the age of 20. Regular echocardiograms can be helpful in detecting concerns early and intervening when possible.
Enlargement of the liver and the spleen is common in Morquio. This is typically lessened with the use of enzyme replacement therapy (ERT). Despite enlargement, function is not compromised. Inguinal hernias can also be seen.
Conductive hearing loss, due to the accumulation of fluid behind the ear drum, can be seen. Myringotomy tubes are typically helpful for this; however, at times, hearing aids are required.
Corneal clouding is typical once patients reach age 5. Glaucoma of the eyes and pigmentary retinal degeneration may occur in older patients. Ophthalmologic examination is needed at frequent intervals.
Cutaneous abnormalities may also be present, including loose, thickened, tough and inelastic skin, particularly of the extremities. Generalized telangiectasia of the face and limbs has also been reported.
Appropriate dental care is required due to the hypoplasia of tooth enamel. Teeth often brown and discolor easily. The permanent posterior teeth have pointed cusps; there is often times pitting of the buccal surfaces. The teeth are also widely spaced.
Intelligence and mentality is typically not impaired in Morquio type A. However, progressive mental deficiency does occur in Morquio Type B.