Byler Disease

Byler disease is an inherited condition caused by a faulty gene. In children with Byler disease, cells in the liver cannot release bile, a fluid that helps the body digest food. As a result, bile builds up in the liver, leading to symptoms such as jaundice, itching, impaired growth, and delayed puberty. Byler disease is one of a group of diseases known as progressive familial intrahepatic cholestasis.

  • Progressive: it gets worse over time.
  • Familial: it runs in families.
  • Intrahepatic: it occurs inside the liver.
  • Cholestasis: poor bile flow.

Children are typically around 3 months old when diagnosed with Byler disease. 

What to Expect

If your child has been diagnosed with Byler disease, we want you to know that you are not alone – the Center for Rare Disease Therapy is here to help. Here’s what you can expect when you come to us for a consultation.

How quickly can we get an appointment?

An appointment with one of our pediatric liver specialists will be scheduled within a reasonable time based on our child’s condition. We will require a copy of your child's medical records and will determine how soon your child should be seen based on their medical information. Reviewing your child's records ahead of the first appointment allows us to avoid repeating tests that your child has already had and to coordinate visits with other specialists as needed.

To make an appointment, please call Jodie Vento at 412-692-7273 or send an email to

How long should we expect our first visit with the doctor to take?

You can expect your first visit to take about 3 to 4 hours.

What will happen during our first visit?

Your child will receive a complete evaluation to establish or confirm a precise diagnosis and determine how much the disease has affected the child.

Because we work as a team at the Center for Rare Disease Therapy, your child may be seen by other specialists, if not on the first visit, then on follow-up visits, including a hearing specialist, a surgeon, a nutritionist, and a genetic counselor.

We understand that the whole family is affected when a child has a rare disease. We see each family as our partner in caring for their child. We think the best approach to caring for a child with a rare disease emerges when we combine our depth of experience in rare diseases with your expertise in what’s best for your child.

We will talk with you about what we think is likely to happen with your child in the near future and about options we can suggest for treating and caring for your child. If surgery is an option, we will help you understand what the surgery entails and what you may need to do to prepare for it. We will also talk with you about what you can do at home to care for your child and improve his or her quality of life. Please feel free to ask our specialists any questions you have about your child’s disease, treating and caring for your child, or anything else that is on your mind.

By the end of your visit, you will have a care plan tailored to your child’s needs and an appointment for a follow-up visit in 3 months. You will be introduced to our clinical nurse practitioner, who is available by phone or video conference to help you with any concerns you have between now and your next appointment.

How long might we have to wait for test results?

Depending upon the types of tests that the doctors order, you can expect to receive a phone call within 2 weeks to explain test results and discuss recommended next steps. Test results are also available on Children's patient portal, myCHP, which is provided at no cost to patients, parents, and guardians.

Center for Rare Disease Therapy patient storiesMeet Our Patients

Learn how families are finding help and hope through the expertise of the Center for Rare Disease Therapy at Children’s Hospital of Pittsburgh of UPMC.

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Clinical Studies

Please explore these opportunities to participate in a clinical study for Byler disease:

  • Longitudinal Study of Genetic Causes of Intrahepatic Cholestasis

Contact Us

At the Center for Rare Disease Therapy, every child diagnosed with a rare disease receives an individualized treatment plan and family-centered care.

For an appointment, consultation, or patient referral with an expert at Children’s Hospital of Pittsburgh of UPMC for a child diagnosed with Byler disease, please contact:

Jodie Vento, MGC, LCGC
Phone: +1-412-692-RARE or 412-692-7273