Familial hypercholanemia

Alternative name(s) : FHCA

Gene_locus : 2

Mutation : 3

OMIM : 602938 , 607748

Comment
(from OMIM) Familial hypercholanemia (60748) is characterized by elevated serum bile acid concentrations, itching, and fat malabsorption. Carlton et al. (2003) studied this disorder in 17 individuals in 12 families of Lancaster County Old Order Amish descent. In 6 families, affected individuals were homozygous for a missense mutation in the gene encoding tight junction protein-2 (TJP2)(not an a/b hydrolase). In 2 families, affected individuals were homozygous for an M76V mutation in BAAT. In 2 families, the affected individuals were homozygous for the TJP2 missense mutation and heterozygous for the BAAT mutation, and in 1 family affected individuals were homozygous for the BAAT mutation and heterozygous for the TJP2 mutation. Carlton et al. (2003) postulated oligogenic inheritance of familial hypercholanemia. In a patient with hypercholanemia, Zhu et al. (2003) identified compound heterozygosity for 2 mutations in the EPHX1 gene, which resulted in a significant decrease in EPHX1 promoter activity.