Genetic Variation in the Indoleamine 2,3-Dioxygenase Gene in Pre-eclampsia

Problem To investigate the contribution of genomic variations in the indoleamine 2,3-dioxygenase (IDO) gene to the onset of pre-eclampsia.Method of study We examined sequence variations in the IDO1 gene using placental genomic DNA from 35 pre-eclamptic patients and 32 normotensive pregnant women.Results A case-control study revealed that none of the common variants influences the risk of disease. Sequencing of each IDO1 exon in diseased subjects revealed rare variants. This variation, c.-147_150delGAAA, was located within the 5'-untranslated region of the IDO1 gene, and its homozygote was identified only in pre-eclamptic subjects. However, despite the low levels of IDO expression and enzyme activity in the c.-147_150delGAAA homozygote, reporter assays indicated that this variation does not affect gene expression.Conclusion Our findings indicate that genetic alteration of fetal IDO gene does not appear to be a primary cause of pre-eclampsia.