What Is Crigler-Najjar Syndrome?
Crigler-Najjar syndrome is a rare hereditary disease found in children in which a substance processed by the liver, called bilirubin, cannot be changed into its water-soluble form (conjugated bilirubin). The unconjugated bilirubin collects in the child’s liver and spleen, enters circulation, and then builds up in other tissues such as the eyes and skin. This buildup causes jaundice and eventually nerve and brain damage.
Types of Crigler-Najjar syndrome
There are two types of Crigler-Najjar syndrome disorders in pediatric patients. Patients with type I have a deficiency of the liver enzyme called glucuronyl transferase, and patients with type II have a limitation of this enzyme. Type II can be managed by phototherapy and the drug phenobarbital (which helps the body produce more glucuronyl transferase), and does not require liver transplantation. Type I, on the other hand, is more serious and potentially life-threatening.
Crigler-Najjar Syndrome Symptoms in Children
In a baseline case of this condition, the child is jaundiced and the following Crigler-Najjar symptoms may occur:
- Fatigue
- Abdominal pain related to biliary stones
Symptoms of the acute stage of the illness are caused by an increase in unconjugated bilirubin and considered medical emergencies:
- Diarrhea
- Vomiting
- Fever
- Confusion
- Slurred speech
- Difficulty swallowing
- Change in gait, staggering, frequent falling
- Seizures
Crigler-Najjar Syndrome Diagnosis
Crigler-Najjar syndrome is common among the relatively small population of the Amish and Mennonite communities. Although Crigler-Najjar is an extremely rare disorder, with only about 100 known cases worldwide, 20 percent of these cases are seen in the Pennsylvania Amish.
The baseline disease will show jaundice with no enlarged liver or spleen on abdominal exam. The acute stage of the disease may show an increased heart rate, poor circulation of fluids through the organs (perfusion), improper alignment of the eyes, weak gag reflex, and muscle spasms.
Labwork will show elevated unconjugated bilirubin levels, normal levels of transaminases, low levels of albumin, and the absence of glucuronyl transferase with genetic testing. Imaging studies such as a MRI and EEG may be called for, but an MRI may be normal even after severe injury, unless fatal bilirubin intoxication has occurred. An EEG may help confirm intoxication and recovery.
Crigler-Najjar Syndrome Treatment
Crigler-Najjar syndrome is primarily managed by phototherapy, in which the child is exposed to blue LED light in an apparatus similar to a tanning bed. The light breaks down the unconjugated bilirubin into compounds that are not toxic to tissues. However, phototherapy is a tedious process, requiring 10-12 hours of therapy per day. The prolonged exposure to light causes the child’s skin to thicken, increasing the need for a more intense phototherapy regimen. The need for phototherapy significantly impedes their quality of life.
Daily Crigler-Najjar syndrome treatment medications include Actigall®, phenobarbital, vitamin E, vitamin C, coenzyme Q, L-carnitine, and creatine. When unconjugated bilirubin reaches toxic levels, the disease is managed by aggressive intravenous fluid hydration, management of elevated glucose, administration of albumin, and possibly plasma exchange with the hope of avoiding catastrophic, neurological consequences.
Liver transplantation is a potentially life-saving treatment for Crigler-Najjar patients. A new liver has the ability to convert unconjugated bilirubin (that is unable to be excreted from the body) into conjugated bilirubin (that is able to be excreted from the body). Immunosuppressant medication (i.e., Prograf®) is required to prevent liver rejection and prophylactic medication (Bactrim®) is used against pneumocystis carinii pneumonia. Typically, these are the only two medications Crigler-Najjar patients require one year post transplantation. The patients still have the gene mutation causing the deficiency of glucuronyl transferase and can still pass the abnormality to their children.
A liver transplantation enables a Crigler-Najjar patient to function without the use of phototherapy and without the fear of neurological devastation and death from toxic unconjugated bilirubin levels.
Learn about other Liver Disease States.
