The early infantile form of galactosialidosis is associated with hydrops fetalis, inguinal hernia, and hepatosplenomegaly. Additional features include abnormal bone development (dysostosis multiplex) and distinctive facial features that are often described as 'coarse.' Some infants have an enlarged heart; an eye abnormality called a cherry-red spot (identified through an eye examination); and kidney disease that can progress to kidney failure. Infants with this form are usually diagnosed between birth and 3 months of age.
The late infantile form of galactosialidosis shares some features with the early infantile form, although the signs and symptoms are somewhat less severe and begin later in infancy. This form is characterized by short stature, dysostosis multiplex, heart valve problems, hepatosplenomegaly, and 'coarse' facial features. Other symptoms seen in some individuals with this type include intellectual disability, hearing loss, and a cherry-red spot. Children with this condition typically develop symptoms within the first year of life.
The juvenile/adult form of galactosialidosis has signs and symptoms that are somewhat different than those of the other two types. This form is distinguished by difficulty coordinating movements (ataxia), muscle twitches (myoclonus), seizures, and progressive intellectual disability. People with this form typically also have dark red spots on the skin (angiokeratomas), abnormalities in the bones of the spine, 'coarse' facial features, a cherry-red spot, vision loss, and hearing loss. The age at which symptoms begin to develop varies widely among affected individuals, but the average age is 16.
The Human Phenotype Ontology (HPO) provides the following list of features that have been reported in people with this condition. Much of the information in the HPO comes from Orphanet, a European rare disease database. If available, the list includes a rough estimate of how common a feature is (its frequency). Frequencies are based on a specific study and may not be representative of all studies. You can use the MedlinePlus Medical Dictionary for definitions of the terms below.
|Signs and Symptoms||Approximate number of patients (when available)|
|Abnormality of the macula||90%|
|Coarse facial features||90%|
|Opacification of the corneal stroma||90%|
|Autosomal recessive inheritance||-|
|Cherry red spot of the macula||-|
|Decreased beta-galactosidase activity||-|
|Severe short stature||-|
Galactosialidosis is caused by mutations in the CTSA gene. The CTSA gene provides instructions for making a protein called cathepsin A, which is active in cellular compartments called lysosomes. These compartments contain enzymes that digest and recycle materials when they are no longer needed. Cathepsin A works together with two enzymes, neuraminidase 1 and beta-galactosidase, to form a protein complex. This complex breaks down sugar molecules (oligosaccharides) attached to certain proteins (glycoproteins) or fats (glycolipids). Cathepsin A is also found on the cell surface, where it forms a complex with neuraminidase 1 and a protein called elastin binding protein. Elastin binding protein plays a role in the formation of elastic fibers, a component of the connective tissues that form the body's supportive framework.
CTSA mutations interfere with the normal function of cathepsin A. Most mutations disrupt the protein structure of cathepsin A, impairing its ability to form complexes with neuraminidase 1, beta-galactosidase, and elastin binding protein. As a result, these other enzymes are not functional, or they break down prematurely.
Galactosialidosis belongs to a large family of lysosomal storage disorders, each caused by the deficiency of a specific lysosomal enzyme or protein. In galactosialidosis, impaired functioning of cathepsin A and other enzymes causes certain substances to accumulate in the lysosomes.
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.
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.
Nonprofit support and advocacy groups bring together patients, families, medical professionals, and researchers. These groups often raise awareness, provide support, and develop patient-centered information. Many are the driving force behind research for better treatments and possible cures. They can direct people to research, resources, and services. Many groups also have experts who serve as medical advisors. Visit their website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.
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.
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.
Gordon Research Conference and Gordon Research Seminar on Lysosomes and Endocytosis
Sunday, June 15, 2014 -
Friday, June 20, 2014
Location: Proctor Academy, Andover, NH
Description: The main goal of the Lysosomes and Endocytosis GRC is to foster the dissemination of current research results and the establishment of new research areas and new collaborations in the area of the cell biology of endocytosis, lysosomes, endosomes and related organelles. We hope that many of these new directions and collaborations will be directed toward the etiology, diagnosis and treatment of rare genetic diseases such as lysosomal storage disorders, Hermansky-Pudlak syndrome, Chediak-Higashi syndrome, Niemann Pick disease and tuberous sclerosis, among others.
Contact: Alexandra Ainsztein, Ph.D.(301) 594-0828, Alexandra.Ainsztein@nih.gov
Co-funding Institute(s): National Institute of General Medical Sciences, Office of Rare Diseases Research
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My daughter has been diagnosed with galactosialidosis via a lysosomal enzyme assay. A skin biopsy is pending. I am considering a stem cell transplant in the hopes of improving her prognosis. She is just 1 year and 5 months old and has already begun to show symptoms. How is galactosialidosis treated? What is the prognosis? See answer