National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Mucopolysaccharidosis type IVA


Other Names:
MPS IVA; MPS 4A; Morquio A disease; MPS IVA; MPS 4A; Morquio A disease; Galactosamine-6-sulfatase deficiency; GALNS deficiency; Morquio disease type A; MPS4A; MPSIVA; Mucopolysaccharidosis type 4A; N-acetylgalactosamine-6-sulfate sulfatase deficiency; Morquio syndrome A See More
Categories:
This disease is grouped under:
Mucopolysaccharidosis type IVA (MPS IVA, also called Morquio syndrome, type A) is a metabolic condition that primarily affects the skeleton. The severity, age of onset, and associated symptoms vary significantly from person to person and range from a severe and rapidly progressive, early-onset form to a slowly progressive, later-onset form. The severe form is usually diagnosed between ages 1 and 3, while the milder form may not become evident until late childhood or adolescence. Signs and symptoms include various skeletal abnormalities such as short stature, knock knees, pectus carinatum, and malformations of the spine, hips and wrists. Affected people may also experience involvement of other organ systems such as respiratory problems, valvular heart disease, hearing impairment, corneal clouding, dental abnormalities, hepatomegaly, and spinal cord compression.[1][2] MPS IVA is caused by changes (mutations) in the GALNS gene and is inherited in an autosomal recessive manner.[3] Treatment is based on the signs and symptoms present in each person.[1]
Last updated: 4/4/2016

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
Percent of people who have these symptoms is not available through HPO
Abnormal heart valve morphology 0001654
Autosomal recessive inheritance 0000007
Carious teeth
Dental cavities
Tooth cavities
Tooth decay
[ more ] 		0000670
Cervical myelopathy 0002318
Cervical subluxation 0003308
Chondroitin sulfate excretion in urine 0012070
Coarse facial features
Coarse facial appearance
0000280
Constricted iliac wings 0003277
Coxa valga 0002673
Disproportionate short-trunk short stature
Disproportionate short-trunked dwarfism
Disproportionate short-trunked short stature
Short-trunked dwarfism
[ more ] 		0003521
Epiphyseal deformities of tubular bones 0003053
Flaring of rib cage 0000904
Genu valgum
Knock knees
0002857
Grayish enamel
Gray colored tooth enamel
Greyish enamel
[ more ] 		0000683
Hearing impairment
Deafness
Hearing defect
[ more ] 		0000365
Hepatomegaly
Enlarged liver
0002240
Hyperlordosis
Prominent swayback
0003307
Hypoplasia of the odontoid process 0003311
Inguinal hernia 0000023
Joint laxity
Joint instability
Lax joints
Loose-jointedness
Loosejointedness
[ more ] 		0001388
Juvenile onset
Signs and symptoms begin before 15 years of age
0003621
Keratan sulfate excretion in urine 0012069
Kyphosis
Hunched back
Round back
[ more ] 		0002808
Large elbow 0030865
Mandibular prognathia
Big lower jaw
Increased projection of lower jaw
Increased size of lower jaw
Large lower jaw
Prominent chin
Prominent lower jaw
[ more ] 		0000303
Metaphyseal widening
Broad wide portion of long bone
0003016
Opacification of the corneal stroma 0007759
Osteoporosis 0000939
Ovoid vertebral bodies 0003300
Platyspondyly
Flattened vertebrae
0000926
Pointed proximal second through fifth metacarpals 0001223
Prominent sternum 0000884
Recurrent upper respiratory tract infections
Recurrent colds
0002788
Restrictive ventilatory defect
Stiff lung or chest wall causing decreased lung volume
0002091
Scoliosis 0002650
Ulnar deviation of the wrist 0003049
Wide mouth
Broad mouth
Large mouth
[ more ] 		0000154
Widely spaced teeth
Wide-spaced teeth
Widely-spaced teeth
[ more ] 		0000687
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Last updated: 7/1/2020

Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

The resources below provide information about treatment options for this condition. If you have questions about which treatment is right for you, talk to your healthcare professional.

Management Guidelines

  • Project OrphanAnesthesia is a project whose aim is to create peer-reviewed, readily accessible guidelines for patients with rare diseases and for the anesthesiologists caring for them. The project is a collaborative effort of the German Society of Anesthesiology and Intensive Care, Orphanet, the European Society of Pediatric Anesthesia, anesthetists and rare disease experts with the aim to contribute to patient safety.

FDA-Approved Treatments

The medication(s) listed below have been approved by the Food and Drug Administration (FDA) as orphan products for treatment of this condition. Learn more orphan products.

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • ClinicalTrials.gov lists trials that are related to Mucopolysaccharidosis type IVA. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

Patient Registry

  • The Lysosomal Disease Network is a team of doctors, nurses, research coordinators, and research labs throughout the U.S., working together to improve the lives of people with this condition through research. The Lysosomal Disease Network has a registry for patients who wish to be contacted about clinical research opportunities.

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

Living with a genetic or rare disease can impact the daily lives of patients and families. These resources can help families navigate various aspects of living with a rare disease.

Financial Resources

  • National Organization for Rare Disorders (NORD) has Disease-Specific Assistance Programs designed to help patients with out-of-pocket costs such as monthly insurance premiums or deductibles. In addition, some programs may provide financial assistance for additional expenses related to a patient's diagnosis such as travel to see a specialist.

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • Genetics Home Reference (GHR) contains information on Mucopolysaccharidosis type IVA. This website is maintained by the National Library of Medicine.
  • MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.
  • The National Institute of Neurological Disorders and Stroke (NINDS) (NINDS) collects and disseminates research information related to neurological disorders. Click on the link to view information on this topic.
  • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

In-Depth Information

  • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Mucopolysaccharidosis type IVA. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.

  1. Debra S Regier, MD, PhD, Matthew Oetgen, MD, and Pranoot Tanpaiboon, MD. Mucopolysaccharidosis Type IVA. GeneReviews. March 2016; http://www.ncbi.nlm.nih.gov/books/NBK148668.
  2. Mucopolysaccharidosis type IV. Genetics Home Reference. July 2010; https://ghr.nlm.nih.gov/condition/mucopolysaccharidosis-type-iv.
  3. MUCOPOLYSACCHARIDOSIS, TYPE IVA. OMIM. September 2015; http://www.omim.org/entry/253000.