Deficiency, UDP-glucuronosyltransferase: Underactivity of a liver enzyme that is essential to the disposal of bilirubin (the chemical that results from the normal breakdown of hemoglobin from red blood cells).
The deficiency of this enzyme (UDP-glucuronosyltransferase) results in a condition called Gilbert's disease in which there are mild elevations of bilirubin pigment in the blood. The elevated bilirubin pigment can sometimes cause mild yellowing (jaundice) of the eyes. People with Gilbert's disease are otherwise entirely normal with no other signs or symptoms and their liver enzymes in blood serum are also entirely normal.
There is no need for treatment, and the prognosis (outlook) is excellent.
The gene for UDP-glucuronosyltransferase has been mapped on a non-sex chromosome (chromosome 2). A single dose of the Gilbert version of the gene is enough to produce Gilbert's disease. The condition is said therefore to be an autosomal dominant trait. If someone has Gilbert's disease, the chance of their transmitting the Gilbert gene to each of their children is one-half (50%) and each child who gets the gene gets Gilbert's disease.
Gilbert's disease is a frequent finding in people in the U.S. and Europe. The condition is usually detected in the course of routine blood screening. Gilbert's disease is an enzyme abnormality of no health consequence.