||Unknown; approximately 120 affected individuals have been identified, but many more may be undiagnosed, due to mild symptoms or confusion with cerebral palsy
||1 in 100 in Ashkenazi Jews
What is mucolipidosis IV?
Mucolipidosis IV (MLIV) was first described in 1974, but there is still a great deal that is not known about the condition. It is part of a group known as genetic lysosomal storage diseases, in which cells can’t produce an enzyme which allows them to break down certain compounds. These compounds then build up and impair cell functions. MLIV is a disease which affects the brain and nervous system, but a specific cause has not yet been identified. Most reported cases of this disease have been severe, with onset during the first year of life, but some individuals with milder disease have also been seen.
What are the symptoms?
MLIV is often mistaken for cerebral palsy. In the first year of life individuals display significant delays in both motor and cognitive development and often have low muscle tone. Most do not develop speech or the ability to walk independently. Vision may be normal initially, but progressive visual impairment ensues over the first decade of life due to corneal clouding and retinal degeneration. Sensitivity to light and crossed eyes are also common findings, and blindness may occur later in life.
Is there treatment available?
No effective treatment or cure is available at this time. Supportive care, such as physical, speech or occupational therapy may be recommended to improve quality of life. Other measures such as corneal surgery may provide temporary relief of symptoms.
What is the life expectancy of someone with MLIV?
Since the disease was only first described in 1974, little is known about life expectancy for someone with MLIV. Individuals with this disorder are thought to have a reduced life expectancy, with current reported cases ranging from one to 45 years of age.
How do I find out if I am a carrier?
Genetic testing of the MLIV gene can identify 95% of Ashkenazi Jewish carriers. Visit Screening and Counseling for more information. The Center encourages prospective parents to meet with a genetic counselor and get tested before conception, in order to make the best health care decisions for their families.
How is MLIV diagnosed?
A physician knowledgeable of its symptoms may recommend genetic testing of the MLIV gene, which involves a simple blood test. Biochemical testing and/or a skin biopsy may also be recommended.
Is prenatal diagnosis available?
Testing is available to those with a previously affected child or to couples found to be at risk as carriers.
How can I find out more about MLIV?
Mucolipidosis IV Foundation
The Mucolipidosis IV Foundation provides information that both parents and professionals will find helpful. The site provides resources for all affected by the disease as well as regular updates regarding new research and findings.
Canadian Mucopolysaccharide and Related Diseases Society
The Canadian MPS Society is committed to providing support to individuals and families affected with MPS and related diseases, educating medical professionals and the general public about MPS, and raising funds for research so that one day there will be cures for all MPS and related diseases. There is relevant information for those affected by Mucolipidosis IV within the site.
National MPS Society
The National MPS Society exists to find cures for MPS and related diseases. It provides hope and support for affected individuals and their families through research, advocacy and awareness of these devastating diseases.