Congenital Bile Acid Synthesis Defect Type III


Congenital Bile Acid Synthesis Defect Type III (CBASIII) is caused by a defect in 25-hydroxycholesterol 7-alpha-hydroxylase, which plays a role in synthesis of bile acids. The synthesis of primary bile acids from cholesterol occurs via two pathways: the classic neutral pathway involving cholesterol 7-alpha-hydroxylase (CYP7A1), and the acidic pathway involving a distinct microsomal oxysterol 7-alpha-hydroxylase (CYP7B1). CBASIII is characterized by accumulation of bile acids in the urine. Symptoms include severe cholestasis, cirrhosis, and liver failure.

Pathway legend Zoom in

Pathway Image

Pathway legend Zoom in

References

  1. Uniprot: O75881
  2. OMIM: Entry 603711
  3. Hentati A, Pericak-Vance MA, Hung WY, Belal S, Laing N, Boustany RM, Hentati F, Ben Hamida M, Siddique T: Linkage of ‘pure’ autosomal recessive familial spastic paraplegia to chromosome 8 markers and evidence of genetic locus heterogeneity. Hum Mol Genet. 1994 Aug;3(8):1263-7. Pubmed
  4. Martin C, Ross M, Chapman KE, Andrew R, Bollina P, Seckl JR, Habib FK: CYP7B generates a selective estrogen receptor beta agonist in human prostate. J Clin Endocrinol Metab. 2004 Jun;89(6):2928-35. Pubmed
  5. Setchell KD, Schwarz M, O’Connell NC, Lund EG, Davis DL, Lathe R, Thompson HR, Weslie Tyson R, Sokol RJ, Russell DW: Identification of a new inborn error in bile acid synthesis: mutation of the oxysterol 7alpha-hydroxylase gene causes severe neonatal liver disease. J Clin Invest. 1998 Nov 1;102(9):1690-703. Pubmed