Overview
Free sialic acid storage disease, infantile form — also known as infantile sialic acid storage disease (ISSD) — is a very rare and severe inherited metabolic disorder. It belongs to a group of conditions called lysosomal storage diseases. In this disease, the body cannot properly transport a sugar molecule called sialic acid (also known as N-acetylneuraminic acid) out of the lysosomes, which are the recycling centers inside cells. As a result, sialic acid builds up to toxic levels in cells throughout the body, causing widespread damage. Babies with ISSD typically show signs of the disease before or shortly after birth. Common features include severe developmental delay, weak muscle tone (hypotonia), coarse facial features, an enlarged liver and spleen, and a swollen abdomen often caused by fluid buildup (ascites). Many affected infants also have bone abnormalities, pale skin, and failure to thrive. The condition is progressive, meaning it gets worse over time. Unfortunately, there is currently no cure for ISSD. Treatment is supportive and focuses on managing symptoms and improving comfort. This may include nutritional support, physical therapy, and treatment of infections or other complications. Because the disease is so severe, most affected children have a significantly shortened lifespan, often not surviving beyond early childhood. Research into potential therapies is ongoing, but effective disease-modifying treatments have not yet been developed.
Also known as:
Key symptoms:
Severe low muscle tone (floppy baby)Coarse facial featuresEnlarged liver and spleenSwollen abdomen from fluid buildupFailure to grow and gain weightSevere intellectual disabilityPale or fair skin and hairBone abnormalitiesDelayed or absent developmental milestonesFrequent infectionsSeizuresHeart problemsKidney problemsSwelling of the body (hydrops fetalis in severe cases)Difficulty feeding
Autosomal recessive
Passed on when both parents carry the same gene change; often skips generations
Neonatal
Begins at or shortly after birth (first 4 weeks)
FDA & Trial Timeline
1 eventCibacalcin: FDA approved
Treatment of symptomatic Paget's disease (osteitis deformans).
Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.
Treatments
No FDA-approved treatments are currently listed for Free sialic acid storage disease, infantile form.
View clinical trials →Clinical Trials
View all trials with filters →No actively recruiting trials found for Free sialic acid storage disease, infantile form at this time.
New trials open frequently. Follow this disease to get notified.
Specialists
View all specialists →No specialists are currently listed for Free sialic acid storage disease, infantile form.
Treatment Centers
8 centersBaylor College of Medicine Rare Disease Center ↗
Baylor College of Medicine
📍 Houston, TX
🏥 NORDStanford Medicine Rare Disease Center ↗
Stanford Medicine
📍 Stanford, CA
🔬 UDNNIH Clinical Center Undiagnosed Diseases Program ↗
National Institutes of Health
📍 Bethesda, MD
🔬 UDNUCLA UDN Clinical Site ↗
UCLA Health
📍 Los Angeles, CA
🔬 UDNBaylor College of Medicine UDN Clinical Site ↗
Baylor College of Medicine
📍 Houston, TX
🔬 UDNHarvard/MGH UDN Clinical Site ↗
Massachusetts General Hospital
📍 Boston, MA
🏥 NORDMayo Clinic Center for Individualized Medicine ↗
Mayo Clinic
📍 Rochester, MN
👤 Mayo Clinic Center for Individualized Medicine
🏥 NORDUCLA Rare Disease Day Program ↗
UCLA Health
📍 Los Angeles, CA
Financial Resources
1 resourcesCibacalcin
Novartis Pharmaceutical Corporation
Travel Grants
No travel grants are currently matched to Free sialic acid storage disease, infantile form.
Community
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Caregiver Resources
NORD Caregiver Resources
Support, advocacy, and financial assistance for caregivers of rare disease patients.
Mental Health Support
Rare disease caregiving can be isolating. Connect with counseling and peer support.
Family & Caregiver Grants
Financial assistance programs specifically for caregivers of rare disease patients.
Social Security Disability
Learn how rare disease patients may qualify for SSDI/SSI benefits.
Questions for your doctor
Bring these to your next appointment
- Q1.What is the expected course of this disease for my child specifically?,What supportive treatments can help improve my child's comfort and quality of life?,Should we involve a palliative care team, and when?,Are there any clinical trials or research studies we could participate in?,What should we watch for that would require emergency medical attention?,What does genetic counseling mean for our family and future pregnancies?,Can you connect us with other families affected by this condition or support organizations?
Common questions about Free sialic acid storage disease, infantile form
What is Free sialic acid storage disease, infantile form?
Free sialic acid storage disease, infantile form — also known as infantile sialic acid storage disease (ISSD) — is a very rare and severe inherited metabolic disorder. It belongs to a group of conditions called lysosomal storage diseases. In this disease, the body cannot properly transport a sugar molecule called sialic acid (also known as N-acetylneuraminic acid) out of the lysosomes, which are the recycling centers inside cells. As a result, sialic acid builds up to toxic levels in cells throughout the body, causing widespread damage. Babies with ISSD typically show signs of the disease bef
How is Free sialic acid storage disease, infantile form inherited?
Free sialic acid storage disease, infantile form follows a autosomal recessive inheritance pattern. Genetic counseling can help families understand recurrence risk and testing options.
At what age does Free sialic acid storage disease, infantile form typically begin?
Typical onset of Free sialic acid storage disease, infantile form is neonatal. Age of onset can vary across affected individuals.
What treatment and support options exist for Free sialic acid storage disease, infantile form?
1 patient support program are currently tracked on UniteRare for Free sialic acid storage disease, infantile form. See the treatments and support programs sections for copay assistance, eligibility, and contact details.