Criggler Najjar Syndrome

Criggler Najjar syndrome

(CNS) is a rare genetic condition most commonly seen in infants. It can lead to hyperbilirubinemia or an increase in the levels of unconjugated bilirubin ( a chemical obtained from the breakdown of blood) which without effective treatment could cause irreversible brain damage in infants.

It is an extremely rare condition and affects about 1 in 1,000,000 births.

Types of Criggler Najjar Syndrome

Type 1


  • It is associated with neonatal jaundice which is accompanied with high levels of unconjugated bilirubin and can bring about brain damaging kernicterus and death.
  • It is an inherited genetic condition where any manifested abnormality is not detected in the hepatic tissue.
  • The enzyme UGT1A1 is not detected in the tissues of the liver. Hence phenobarbital ( treatment by causing enzyme induction) is not effective.
  • The patient undergoes genetic mutations where a difficulty is faced conjugating (unite together to form a bond) bilirubin as well as substrates found in other drugs.
  • Bile is pale in color.
  • The serum bilirubin levels could go up to a few hundred times above the normal reference range.
  • Intense jaundice affects the infant and can persist for some time.


  • It is primarily treated with phototherapy or light therapy even up to 12 hours per day depending on the intensity of the condition. The child is exposed to daylight or a light source with a specific wavelength or a full spectrum source of light as the need may be. This therapy brings about marked improvement in blood properties and blood circulation. The unconjugated free bilirubin in the blood is dealt with and is converted into compound which the infant can discharge with feces and urine.
  • Enzyme therapy where heme oxygenase ( enzymes which helps in the breakdown of blood into bilirubin) inhibitors are induced to reduce the levels of free bilirubin in blood.
  • Oral calcium phosphate and carbonate to chemically react and bond with the available bilirubin in the gut.
  • The ultimate step to treat the disease when all other measures fail and most importantly prevent brain damage would be liver transplantation.

Type 2


  • It is associated with lower serum bilirubin levels than Type 1 and is generally present without any brain damage or kernicterus.
  • It is also an inherited genetic condition.
  • The enzyme UGT1A1 is detected in the hepatic tissue albeit in very small amounts.
  • This disease could be detected later on in life.
  • Bile is dark and pigmented.


  • Type 2 can be very well treated with phenobarbital treatment. It is an anticonvulsant which causes enzyme induction.
  • It can bring about a decrease in serum bilirubin levels by as much as 25%.

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