Overview
Congenital portosystemic shunt (CPSS) is a rare blood vessel abnormality that a person is born with. Normally, blood from the intestines, stomach, and spleen travels through the portal vein to the liver, where it gets cleaned and processed. In CPSS, an abnormal connection (called a shunt) allows this blood to bypass the liver and flow directly into the general bloodstream. This means the liver cannot filter out toxins, ammonia, and other harmful substances the way it should. The condition is also sometimes called congenital portosystemic venous shunt or Abernethy malformation, especially when the shunt is located outside the liver. Because the liver is not doing its full filtering job, toxins can build up in the blood and reach the brain, causing a condition called hepatic encephalopathy. This can lead to confusion, behavior changes, and developmental problems. Some people also develop liver tumors, high blood pressure in the lungs (pulmonary hypertension), or heart problems over time. Symptoms can range from very mild to quite serious, and some people are not diagnosed until adulthood. Treatment depends on the type and location of the shunt. Some shunts can be closed through a minimally invasive procedure or surgery, which may allow the liver to recover much of its normal function. Others require liver transplantation. Early diagnosis and treatment can greatly improve outcomes, making awareness of this condition very important.
Also known as:
Key symptoms:
Confusion or mental fogginess (hepatic encephalopathy)Behavioral changes or mood swingsDevelopmental delays in childrenPoor growth or failure to thrive in infantsElevated ammonia levels in the bloodLiver tumors (benign or malignant)High blood pressure in the lungs (pulmonary hypertension)Shortness of breathLow blood sugar (hypoglycemia)Abnormal liver blood testsEnlarged liver or spleenHeart problems or abnormal heart structureFatigue and low energy
Multifactorial
Caused by a mix of several genes and environmental factors
Variable
Can begin at different ages, from infancy through adulthood
FDA & Trial Timeline
2 eventsProf. Valérie Mc Lin
Prof. Valérie Mc Lin
Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.
Treatments
No FDA-approved treatments are currently listed for Congenital portosystemic shunt.
1 clinical trialare actively recruiting — trials can provide access to cutting-edge therapies.
View clinical trials →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
Travel Grants
No travel grants are currently matched to Congenital portosystemic shunt.
Community
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Caregiver Resources
NORD Caregiver Resources
Support, advocacy, and financial assistance for caregivers of rare disease patients.
Mental Health Support
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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 type of portosystemic shunt does my child or I have, and can it be closed?,What are the risks of closing the shunt, and what happens if we do not treat it?,How often do I need imaging to check for liver tumors or other complications?,Should I see a cardiologist or lung specialist to check for pulmonary hypertension?,Are there dietary changes I should make right away to protect my liver and brain?,What signs should prompt me to go to the emergency room?,Is there a specialized center with more experience in this condition that I should be referred to?
Common questions about Congenital portosystemic shunt
What is Congenital portosystemic shunt?
Congenital portosystemic shunt (CPSS) is a rare blood vessel abnormality that a person is born with. Normally, blood from the intestines, stomach, and spleen travels through the portal vein to the liver, where it gets cleaned and processed. In CPSS, an abnormal connection (called a shunt) allows this blood to bypass the liver and flow directly into the general bloodstream. This means the liver cannot filter out toxins, ammonia, and other harmful substances the way it should. The condition is also sometimes called congenital portosystemic venous shunt or Abernethy malformation, especially when
How is Congenital portosystemic shunt inherited?
Congenital portosystemic shunt follows a multifactorial inheritance pattern. Genetic counseling can help families understand recurrence risk and testing options.
Are there clinical trials for Congenital portosystemic shunt?
Yes — 1 recruiting clinical trial is currently listed for Congenital portosystemic shunt on UniteRare. See the clinical trials section on this page for phase, sponsor, and site details sourced from ClinicalTrials.gov.
Which specialists treat Congenital portosystemic shunt?
15 specialists and care centers treating Congenital portosystemic shunt are listed on UniteRare, sourced from ClinicalTrials.gov principal investigators, published research, and the NPPES NPI registry.