damaged, symptoms start to appear. Diagnosis Classification This syndrome has two forms, A and B, referred to as Morquio A and Morquio B syndrome or MPS IVA and MPS IVB. The two forms are distinguished by the gene product involved; Type A involves a malfunction in the GALNS gene, while Type B involves a malfunction of the GLB1 gene. Treatment The treatment for Morquio syndrome consists of prenatal identification and of enzyme replacement therapy. On 12 February 2014, the US Food and Drug Administration approved the drug elosulfase alfa (Vimizim) for treating Type A. Currently, there is no treatment for Type B. Prognosis The lifespan of patients with Morquio syndrome is variable and depends on the subtype. Type A is generally severe, with a life expectancy in the 20s to 30s. In 2016, a man with Morquio syndrome died at the age of 81. One study found that the mean life expectancy for patients in the United Kingdom was 25.30, with a standard deviation of 17.43 years. On average, female patients lived 4 years longer than male patients. Respiratory failure was the primary cause of death in 63% of patients. Other causes of death were cardiac failure (11%), post-traumatic organ failure (11%), complications of surgery (11%), and heart attack (4%). Life expectancy has been increasing since the 1980s. The average age at death due to respiratory failure improved from 17.42 years old in the 1980s to 30.74 years old in the 2000s. History The condition was first described, simultaneously and independently, in 1929, by Luis Morquio (1867–1935), a prominent Uruguayan physician who discovered it in Montevideo, and James Frederick Brailsford (1888–1961), an English radiologist in Birmingham, England. They both recognized the occurrence of corneal clouding, aortic valve disease, and urinary excretion of keratan sulfate. Morquio observed the disorder in four siblings in a family of Swedish descent and reported his observations in French. See also Hurler syndrome (MPS I) Hunter syndrome (MPS II) Sanfilippo syndrome (MPS III) Dwarfism References External links Autosomal recessive disorders Proteoglycan metabolism disorders Rare syndromes