Dubin-Johnson syndrome is a disorder passed down through families (inherited) in which a person has mild jaundice throughout life.

Dubin-Johnson syndrome is a very rare genetic disorder. In order to inherit the condition, a child must get a copy of the defective gene from both parents.

The syndrome interferes with the body's ability to move bilirubin from the liver. Bilirubin is produced when the liver breaks down worn-out red blood cells. It normally moves through the bile produced by the liver and into the bile ducts, past the gallbladder, and into the digestive system.

When bilirubin is not properly processed, it builds up in the bloodstream and causes the skin and the whites of the eyes to turn yellow (jaundiced). Severely high levels of bilirubin can damage the brain and other organs.

People with Dubin-Johnson syndrome have lifelong mild jaundice that may be made worse by:

• Alcohol
• Birth control pills
• Infection
• Other environmental factors that affect the liver
• Pregnancy

Mild jaundice, which may not appear until puberty or adulthood, is the only symptom of Dubin-Johnson syndrome.

The following tests can help diagnose this syndrome:

• Liver biopsy
• Serum bilirubin
• Urinary coproporphyrin levels

No specific treatment is required.

The outlook is very positive. Dubin-Johnson syndrome generally does not shorten a person's life span.

Complications are unusual but may include the following:

• Severe jaundice
• Reduced liver function

Call your health care provider if any of the following occurs:

• Jaundice is severe.
• Jaundice gets worse over time.
• Abdominal painor other symptoms are also present (may indicate another disorder is causing the jaundice).

Genetic counseling may be helpful for people who wish to have children and have a family history of Dubin-Johnson syndrome.

Porphyrins are a group of chemicals that help form many important substances in the body, including hemoglobin, the protein in red blood cells that carries oxygen in the blood.

This article discusses the test to measure the total amount of porphyrins in your blood.

See also: Porphyrins - urine

Protoporphyrin levels; Porphyrins - total; Coproporphyrin levels; PROTO test

Blood is typically drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.

Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.

Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.

The sample is then placed in ice and taken immediately to the laboratory. Three porphyrins can normally be measured in small amounts in human blood. They are:

• Coproporphyrin
• Protoporphyrin (PROTO)
• Uroporphyrin

Protoporphyrin is normally found in the highest amount. Additional tests are needed to show the levels of specific porphyrins.

You should not eat for 12 - 14 hours before this test. You may drink water right before the test. Failure to follow these restrictions may affect the test results.

When the needle is inserted to draw blood, you may feel moderate pain, or only a prick or stinging sensation. Afterward, there may be some throbbing.

This test is used to diagnose porphyrias, a group of rare disorders often passed down through family members.

It may also be used along with other tests to diagnose lead poisoning and certain nervous system and skin disorders.

This test specifically measures total porphyrin levels, but reference values (a range of values seen in a group of healthy people) for the individual components are also included:

• Total porphyrin levels: 16 to 60 mcg/dL
• Coproporphyrin levels: < 2 mcg/dL
• Protoporphyrin levels: 16 to 60 mcg/dL
• Uroporphyrin levels: < 2 mcg/dL

Note: mcg/dL = micrograms per deciliter

Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

Increased levels of coproporphyrins may indicate:

• Congenital erythropoietic porphyria
• Hepatic coproporphyria
• Sideroblastic anemia

Increased protoporphyrin levels may indicate:

• Anemia of chronic disease
• Erythropoietic protoporphyria
• Increased erythropoiesis
• Infection
• Iron deficiency anemia
• Lead poisoning
• Sideroblastic anemia
• Thalassemia
• Variegate porphyria

Increased uroporphyrin levels may indicate:

• Congenital erythropoietic porphyria

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight but may include:

• Excessive bleeding
• Fainting or feeling light-headed
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)

Anderson KE. The porphyrias. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 229.