What is Galactosialidosis?


Deficiency of an enzyme

Galactosialidosis is a rare genetic disorder characterized by the deficiency of an enzyme called protective protein/cathepsin A (PPCA). This enzyme is involved in the normal functioning of lysosomes, which are cellular structures responsible for breaking down various substances.

Galactosialidosis is inherited in an autosomal recessive manner, meaning that an affected individual inherits two copies of the mutated gene, one from each parent.

The deficiency of PPCA leads to the accumulation of certain substances, including glycoproteins and glycolipids, within the lysosomes. This accumulation affects multiple organs and tissues in the body, resulting in a wide range of symptoms. The severity of the condition can vary widely, even among affected individuals within the same family.


The symptoms of galactosialidosis can include developmental delays, intellectual disability, skeletal abnormalities, coarse facial features, enlarged liver and spleen, heart valve abnormalities, muscle weakness, and seizures. Infants with the disorder may have a failure to thrive and may experience an enlarged head size. Other features that can be present include eye abnormalities, hearing loss, and respiratory difficulties.


Galactosialidosis is diagnosed through a combination of clinical evaluation, genetic testing, and enzyme activity assays. There is currently no cure for galactosialidosis, and treatment focuses on managing the symptoms and improving the individual’s quality of life. This may involve a multidisciplinary approach, including supportive therapies such as physical therapy, occupational therapy, and speech therapy. Genetic counseling is also an important aspect for affected individuals and their families.


The long-term outlook for individuals with galactosialidosis can vary depending on the severity of the condition and the specific symptoms present. Some affected individuals may have a more severe form of the disorder that leads to a shortened lifespan, while others may have a milder form with a better prognosis. Research and advancements in understanding the condition are ongoing, which may lead to improved treatments or interventions in the future.

We are currently working on several treatment options. We are very optimistic that a treatment will be available soon, so watch this space.


Milestones in Galactosialidosis


Initial Clinical Biochemical Identification


Juvenile Patient Identified


Cross Correction in Fibroblast


Molecular identification by D’Azzo


Cathepsin A Cloned


Enzymic Activity of Cathepsin A itself Shown


D’Azzo et al using AAV 2/8 PCCA Murine Correction


PCCA ERT in Murine Model


Submitted pre-IND for AAV gene therapy


Promising Response received from FDA in January 2024

March 2024

Funding applications submitted to start the production of AAV

Classification by Phenotype

Affecting individuals from infancy to adulthood

Early Infantile (10-15%)

Rapidly progressive disease

Cardiac failure

Renal failure

Death before the age of 1


Clinical manifestations

    • Fetal Hydrops
    • Progressive Renal Disease
    • Hepatosplenomegaly
    • Splenic Sequestration
    • Hernias
    • Telangiectasia

Late infantile (5-10%)

Dysostosis multiplex

Spine / Thorax

Renal failure (rare)


Cardiac involvement

Hearing Impairments

Visual Impairements


Growth Issue

Height Issue

Arthritis (one case)

Limited CNS manifestations

Juvenile/adult (80%)

Predominate Neurological




Mental retardation

Visual impairment



Approx. 150 Patients in the World


Country Living Deceased Total
Switzerland (TBC)
Mexico (TBC)
Japan 60
USA 12 3 15
Bahrain 7 5 12
Oman 9
Saudi Arabia 7
Germany 3
Turkey 1 5 6
Australia 3
Israel 3
India 3
Spain 2 0 2
UK 1 1 2
Greece 0 1 1
Brazil 20
Qatar 1 0 1
China 0 1 1
Tunisia 1
Czech Republic 0 1 1
Argentina 1 0 1

Get in touch

If you would like more info or would like to collaborate with us to help find a treatment, please contact us using the details below:

You can also join the ISMRD mailing list.

International Directory of Clinicians and Scientists with experience of galactosialidosis are cited here, if you are a patient, parent or professional with an interest in galactosialidosis you may want to get in touch.