Myelopathy and even tetraplegia can result from vertebral compression. Intelligence is often normal although more severely affected individuals may have some cognitive defects due to impaired vision and hearing. Hepatosplenomegaly is common and compromised respiratory function can result in reduced physical stamina. The tongue is usually enlarged. Accumulation of dermatan sulfate in heart valves may produce insufficiency or restriction of outflow. A diagnosis of Maroteaux-Lamy disease can be confirmed by screening for the common genetic mutations or measuring the level of the arylsulfatase B enzyme activity in a blood sample -- a test that has 100 percent accuracy. Once Maroteaux-Lamy disease is diagnosed, testing of all family members and consultation with a professional geneticist is recommended. Carriers are most reliably identified via genetic mutation analysis.