Maternal susceptibility locus for obstetric cholestasis maps to chromosome region 2p13 in Finnish patients.

BACKGROUND

Obstetric cholestasis, attributed to maternal hypersensitivity to estrogens, is a pregnancy-specific disorder characterized by pruritus and biochemical cholestasis in the second or third trimester of pregnancy. The pathophysiology of the disorder is incompletely understood, but the familial nature of the disease has long been recognized. Carriership of long-chain 3-hydroxyacyl-coenzyme A dehydrogenase (LCHAD) deficiency has been reported to be associated with an increased risk of obstetric cholestasis and the gene is located in the p23 region of chromosome 2.

METHODS

On the basis of this information, we conducted population-based linkage disequilibrium (LD) screening to find potential cholestasis-associated loci on chromosome 2. The study was carried out in 47 unrelated control women and in 45 cholestatic women, eight of whom had a positive family history.

RESULTS

During initial screening with chromosome 2-specific microsatellite markers, the tetranucleotide marker D2S1394 was found to be in LD in the 2p13 region. Screening this region with additional microsatellite markers revealed that the adjacent marker D2S1374 was also significantly associated with obstetric cholestasis, whereas no association was found with the markers located in the vicinity of the hydroxyacyl-CoA dehyrogenase/3-ketoacyl-CoA thiolase/enoyl-CoA hydratase, alpha subunit (HADHA) gene.

CONCLUSIONS

Collectively, these data suggest that there may be a novel obstetric cholestasis-associated gene located in the vicinity of the 2p13 LD region.