Introduction
Mucopolysaccharidosis type IVA(MPS IVA, also known as Morquio syndrome, type A) is a metabolic disorder that primarily affects bone. The severity of the onset, age at onset, and related symptoms vary from person to person, ranging from severe and rapidly progressing early onset to slow progression, late onset. Severe forms are usually diagnosed between the ages of 1 and 3, and mild forms may not become apparent until late childhood or adolescence. Signs and symptoms include various skeletal abnormalities such as short stature, knee fracture, carinatum, and deformities of the spine, buttocks and wrists. Affected people may also experience the involvement of other organ systems, such as respiratory diseases, valvular heart disease, hearing impairment, corneal opacity, abnormal teeth, hepatomegaly and spinal cord compression. MPS IVA is caused by changes (mutations) in the GALNS gene and is inherited in an autosomal recessive manner. Treatment is based on each person's signs and symptoms.
Cause
Mutations in the GALNS and GLB1 genes cause MPS IV and are inherited in a genetic recessive manner. These genes provide an illustration of the production of enzymes that participate in the breakdown of large sugar molecules known as glycosaminoglycans (GAGs). GAG was originally called mucopolysaccharide, which is the name of the disease. When MPS IV is caused by a mutation in the GALNS gene, it is called MPS type IV A (MPS IVA), and when it is caused by a mutation in the GLB1 gene, it is called MPS type IV B (MPS IVB). In general, two types of MPS IV cannot be distinguished by their signs and symptoms.
symptom
Signs and symptoms include various skeletal abnormalities such as short stature, knee fracture, carinatum, and deformities of the spine, buttocks and wrists. Affected people may also experience involvement of other organ systems such as respiratory problems, valvular heart disease, hearing impairment, corneal opacity, abnormal teeth, hepatomegaly and spinal cord compression.
diagnosis
Diagnosing genetic or rare diseases is often challenging. Healthcare professionals typically review the patient's medical history, symptoms, physical exams, and laboratory tests to make a diagnosis. The following resources provide information about the diagnosis and testing of this condition. If you have questions about your diagnosis, please contact a health care professional.
Test resource
The Genetic Testing Registry (GTR) provides information on genetic testing for this condition. The target audience for GTR is healthcare providers and researchers. Patients and consumers with specific problems with genetic testing should contact a health care provider or genetics professional.
treatment
The resources below provide information on treatment options for this situation. If you have any questions about which treatment is right for you, talk to your health care professional.
Management guide
The Orphan Anesthesia Program is a program designed to create peer-reviewed, easy-to-access guides for patients with rare diseases and anesthesiologists. The project is the result of a joint effort by the German Association of Anesthesiology and Critical Care, Orphanet, the European Pediatric Anesthesia Association, an anesthesiologist and a rare disease specialist to help patients.
FDA approved treatment
The following drugs have been approved by the US Food and Drug Administration (FDA) as orphan products for the treatment of this condition. Learn more about orphan products.
Elosulfase alfa(trade name: Vimizim) – manufactured by BioMarin Pharmaceutical Inc.
FDA-approved indications: mucopolysaccharidosis type IVA (MPS IVA; Morquio A syndrome)
简体中文