Hepatic Jaundice Due to a Congenital Enzymatic Defect

CLINICAL DIAGNOSTIC MANUAL

Hepatic jaundice from a congenital enzymatic defect refers to the accumulation of bilirubin in the body due to an alteration in the enzymes responsible for its metabolism in the liver. These alterations are usually hereditary and, depending on the type and severity of the enzymatic defect, can manifest from infancy or intermittently throughout life. Among the most common disorders that cause this type of jaundice are Gilbert’s syndrome and Crigler-Najjar syndrome, which affect the process of bilirubin conjugation, preventing its proper elimination.

Pathology	Symptoms and Clinical Signs	Suspicion Diagnosis	Confirmation Diagnosis
Gilbert’s syndrome	Mild intermittent jaundice, triggered by stress, fasting, or illnesses. No other systemic symptoms or evident liver damage.	Increased unconjugated bilirubin, with normal liver tests.	Serum bilirubin measurement (elevation of unconjugated bilirubin) and genetic study showing mutation in the UGT1A1 gene.
Crigler-Najjar syndrome type 1	Severe jaundice from birth, with extremely high levels of unconjugated bilirubin. Risk of kernicterus (brain damage from bilirubin accumulation).	Severe neonatal jaundice with very high bilirubin levels. Family history of severe jaundice or unexplained neonatal deaths.	Serum bilirubins with extremely high levels of unconjugated bilirubin. Genetic study confirming mutation in the UGT1A1 gene.
Crigler-Najjar syndrome type 2	Chronic mild to moderate jaundice, which usually does not lead to severe complications. Less severe than type 1, but with persistent hyperbilirubinemia.	Chronic moderate-intensity jaundice, no signs of kernicterus. Family history of hyperbilirubinemia.	Serum bilirubins with elevated levels of unconjugated bilirubin. Genetic confirmation of UGT1A1 mutation, but with lesser severity.