Complete Information on Crigler Najjar syndrome

Jun 24
07:51

2008

Juliet Cohen

Juliet Cohen

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Crigler-Najjar syndrome is caused by an abnormal gene. The gene fails to make a working enzyme (bilirubin glucuronyltransferase). This enzyme is capable of converting bilirubin into a water-soluble (and therefore easily excreted) form.

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Crigler-Najjar syndrome (CNS) is a rare autosomal recessive disorder of bilirubin metabolism. This causes jaundice (yellow discoloration of skin and eyes) and organ malfunctions. Crigler-Najjar syndrome (CNS) is divided into two types: type I and type II,Complete Information on Crigler Najjar syndrome Articles which is sometimes called Arias syndrome. These two types, along with Gilbert's syndrome and Dubin-Johnson syndrome, make up the four known hereditary defects in bilirubin metabolism. The syndrome is inherited as an autosomal recessive trait. Type I is a very rare disease (estimated at 0.6 - 1.0 per million live births), and consanguinity increases the risk of this condition. Inheritance is autosomal recessive.Infants who inherit the trait from both parents (this is called being homozygous for the abnormal gene) develop severe jaundice (hyperbilirubinemia) beginning a few days after birth. Milder forms of the disease (type II) are not associated with severe toxicity, liver damage, or changes in thinking during childhood.

CNS is caused by alterations in the coding sequence of UGT. This results in complete absence of UGT or the presence of abnormal UGT with reduced or no enzyme activity. Affected individuals still have jaundice, but they have fewer symptoms and less organ damage. CNS occurs in both equally. CNS is an extremely rare disorder that follows an autosomal recessive pattern of inheritance. Incidence is less than 1 case per 1,000,000 births. Symptoms of Crigler-Najjar syndrome include yellow skin (jaundice) and yellow color of the whites of the eyes (icterus) and Confusion and changes in thinking (resulting from brain toxicity of bilirubin).

Treatment usually involves plasma exchange transfusion. This removes the bilirubin-saturated protein from the blood. Long-term phototherapy (bili lights) is started as well. Liver transplantation has been used successfully for some people with type I disease. The phototherapy helps break down the bilirubin into a form which can be excreted in the urine. Oral calcium phosphate may also be given. Children with Crigler-Najjar syndrome type 2 may not require any treatment or may have their excess bilirubin managed with phenobarbital. Genetic counseling is recommended for prospective parents with a family history of Crigler-Najjar syndrome.

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