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Summaries for Bile Acid Synthesis Defect, Congenital, 1

 

NIH Rare Diseases : 49 The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.Orpha Number: 79301Disease definitionCongenital bile acid synthesis defect type 1 (BAS defect type 1) is the most common anomaly of bile acid synthesis (see this term) characterized by variable manifestations of progressive cholestatic liver disease, and fat malabsorption.EpidemiologyPrevalence is unknown but may be around 1-9/1,000,000 for overall BAS defects, excluding cerebrotendinous xanthomatosis.Clinical descriptionThe clinical presentation is heterogeneous, however most patients present with features of neonatal cholestasis. Clinical features include hepatomegaly with or without splenomegaly, jaundice, fat and fat-soluble vitamin malabsorption, and mild steatorrhea. In most cases, pruritus is absent. Liver function tests present elevated serum transaminases (AST, ALT), conjugated hyperbilirubinemia, and normal gamma-GT. The liver histology shows inflammation, giant cells, evidence of cholestasis, and variable degrees of liver fibrosis. The clinical course of early-onset disease is heterogeneous with some patients resolving jaundice and being identified later in life, or with more fulminant disease that results in death or requires liver transplantation at an early age. The disorder may also present as late-onset chronic cholestasis. In such patients, liver disease is not always evident and patients may have fat-soluble vitamin malabsorption with rickets, corrected by vitamin supplementation, and/or other complications including bleeding diathesis (hematochezia or intracranial bleeding), neuroaxonal dystrophy and night blindness. Serum liver enzymes are initially often normal but later show increases with progression of liver disease to fibrosis. Children and adolescents may also present with extensive fibrosis and/or cirrhosis.EtiologyThe disease is caused by a mutation in the gene encoding 3-beta-hydroxy-delta-5-C27 steroid oxidoreductase (HSD3B7, 16p12-p11.2). Transmission is autosomal recessive.Diagnostic methodsDiagnosis is based on detection of sulfate and glycosulfate conjugates of 3-beta-hydroxy-delta-5 bile acids, which are the signature metabolites of this bile acid defect, on liquid secondary ionization mass spectrometry (LSIMS) analysis of urine. Gas chromatography - mass spectrometry (GC-MS) or electroscopy and tandem mass spectrometry may also be used.Differential diagnosisDifferential diagnoses include progressive familial intrahepatic cholestasis, diseases that present with neonatal cholestasis, which includes alpha-1-antitrypsin deficiency of ZZ phenotype, Alagille syndrome, biliary atresia, cystic fibrosis, and metabolic diseases (tyrosinemia type I, galactosemia, hereditary fructose intolerance) (see these terms), diseases that present with fat and fat soluble vitamin malabsorption, including other liver diseases, and intestinal disease, or diseases that present with growth failure.Antenatal diagnosisAntenatal diagnosis can be made on embryonic tissue obtained when there has been a previously identified sibling. Urine LSIMS in a suspect infant can confirm the diagnosis in the first neonatal days.Management and treatmentTreatment is based on oral administration of cholic acid which leads to gradual resolution of biochemical and histologic abnormalities and prevents progression of the disease, even in cases with hepatic fibrosis and cirrhosis. Cholic acid therapy stimulates bile flow and suppresses synthesis of atypical bile acids and production of toxic intermediates via the bile acid pathway linked to the pathogenesis of disease.PrognosisWith early treatment the long-term prognosis is excellent.Visit the Orphanet disease page for more resources. Last updated: 1/1/2011 

 

MalaCards based summary : Bile Acid Synthesis Defect, Congenital, 1, also known as cbas1, is related to cholestasis, progressive familial intrahepatic, 4 and congenital bile acid synthesis defect, and has symptoms including pruritus, failure to thrive and splenomegaly. An important gene associated with Bile Acid Synthesis Defect, Congenital, 1 is HSD3B7 (Hydroxy-Delta-5-Steroid Dehydrogenase, 3 Beta- And Steroid Delta-Isomerase 7). The drugs Doxorubicin and Doxil have been mentioned in the context of this disorder. Affiliated tissues include liver and testes. 

 

Disease Ontology : 12 A congenital bile acid synthesis defect characterized by progressive cholestatic liver disease, giant cell hepatitis, malabsorption of fat and fat-soluble vitamins, increased serum bilirubin and decreased serum cholesterol that has material basis in homozygous or compound heterozygous mutation in the HSD3B7 gene on chromosome 16p. 

 

Genetics Home Reference : 24 Congenital bile acid synthesis defect type 1 is a disorder characterized by cholestasis, a condition that impairs the production and release of a digestive fluid called bile from liver cells. Bile is used during digestion to absorb fats and fat-soluble vitamins, such as vitamins A, D, E, and K. People with congenital bile acid synthesis defect type 1 cannot produce (synthesize) bile acids, which are a component of bile that stimulate bile flow and help it absorb fats and fat-soluble vitamins. As a result, an abnormal form of bile is produced. 

 

OMIM : 53 Congenital defects of bile acid synthesis are autosomal recessive disorders characterized by neonatal onset of progressive liver disease with cholestatic jaundice and malabsorption of lipids and lipid-soluble vitamins from the gastrointestinal tract resulting from a primary failure to synthesize bile acids. Affected infants show failure to thrive and secondary coagulopathy. In most forms of the disorder, there is a favorable response to oral bile acid therapy (summary by Cheng et al., 2003). (607765) 

 

UniProtKB/Swiss-Prot : 71 Congenital bile acid synthesis defect 1: A primary defect in bile synthesis leading to progressive liver disease. Clinical features include neonatal jaundice, severe intrahepatic cholestasis, cirrhosis. 

 

Publications for Bile Acid Synthesis Defect, Congenital, 1

 

Genes for Bile Acid Synthesis Defect, Congenital, 1

 

Genes related to Bile Acid Synthesis Defect, Congenital, 1 (2 elite genes):

 

 - Elite gene About elite gene

 - Cancer Census gene in COSMIC

About Cancer Census gene

#

Symbol

Description Category Score Implication PubmedIds

1

HSD3B7

Hydroxy-Delta-5-Steroid Dehydrogenase, 3 Beta- And Steroid Delta-Isomerase 7 Protein Coding 1650

Molecular basis known 53

Pathogenic 6

Causative germline mutation 55

Causative variation 71

Genetic Tests 28

11067870 3470305 12679481

2

TJP2

Tight Junction Protein 2 Protein Coding 400

Pathogenic 6

Pathways for Bile Acid Synthesis Defect, Congenital, 1

 

GO Terms for Bile Acid Synthesis Defect, Congenital, 1