Dubin-Johnson syndrome 2855703 214251246 2008-05-22T19:16:12Z Arcadian 104523 nav {{refimprove|date=December 2007}} {{Infobox_Disease | Name = {{PAGENAME}} | Image = Bilirubin.svg | Caption = [[Bilirubin]] | DiseasesDB = 3982 | ICD10 = {{ICD10|E|80|6|e|70}} | ICD9 = {{ICD9|277.4}} | ICDO = | OMIM = 237500 | MedlinePlus = | eMedicineSubj = med | eMedicineTopic = 588 | MeshID = D007566 | }} '''Dubin-Johnson syndrome''' is an [[autosomal recessive]] disorder which causes an increase of conjugated [[bilirubin]] without elevation of [[liver]] [[enzymes]] ([[Alanine transaminase|ALT]], [[aspartate transaminase|AST]]). This condition is associated with a defect in the ability of hepatocytes to secrete conjugated [[bilirubin]] into the bile. It is usually diagnosed in early infancy. ==Diagnosis== There is plenty of canalicular multi-drug resistant protein which causes bilirubin transfer to [[bile canaliculi]]. An isoform of this protein is localized to the lateral hepatocyte membrane, allowing transport of [[glucuronide]] and [[glutathione]] conjugates back into the blood. Analysis of urine porphyrins show a normal level of coproporphyrin but the I isomer accounts for 80% of the total (normally 25%) Liver will present with dark pink or black appearance due to [[pigment]] accumulation. The conjugated hyperbilirubinemia is a result of defective endogenous and exogenous transfer of anionic conjugates from hepatocytes into the bile.<ref name="Carter">Suzanne M Carter, MS. eMedicine: Dubin-Johnson Syndrome. January 9, 2007. http://www.emedicine.com/ped/topic621.htm</ref> Pigment deposition in lysosomes causes the liver to turn black. A hallmark of DJS is the unusual ratio between the byproducts of heme biosynthesis. Unaffected subjects have a coproporphyrin III to coproporphyrin I ratio of approximately 3-4:1. In patients with DJS, this ratio is inverted with coproporphyrin III being 3-4x higher then coproporphyrin I. ==Genetics== [[Image:autorecessive.jpg|thumb|right|Dubin-Johnson syndrome has an autosomal recessive pattern of inheritance.]] DJS has a defect in the multispecific anion transporter ([[cMOAT]]) gene (ABC transporter superfamily). Likely a loss of function mutation, since the mutation affects the cytoplasmic / binding domain. ==Prognosis== Prognosis is good, and treatment of this syndrome is usually unnecessary. Most patients are asymptomatic and have normal life spans.<ref name="Carter" /> Some neonates will present with cholestasis.<ref name="Carter" /> Oral contraceptive and pregnancy may lead to overt jaundice and icterus (yellowing of the eyes) ==References== {{reflist}} ==See also== *[[Jaundice]] *[[Gilbert syndrome]] *[[Crigler-Najjar syndrome]] *[[Rotor syndrome]] {{Heme metabolism disorders}} [[Category:Gastroenterology]] [[Category:Hepatology]] [[Category:Syndromes]] [[Category:Genetic disorders]] [[Category:Autosomal recessive disorders]] {{genetic-disorder-stub}} [[de:Dubin-Johnson-Syndrom]] [[es:Síndrome de Dubin-Johnson]] [[pl:Zespół Dubina-Johnsona]]