Mice, genetically-engineered to be deficient in an enzyme called COMT, were found to develop pre-eclampsia.
The researchers from Harvard Medical School said low levels of COMT are also seen in pregnant women with the condition – which is dangerous for mother and baby.
But obstetric experts said a test would still be a long way off.
Pre-eclampsia accounts for 15% of all premature deliveries in the UK.
This is because the only way to completely cure pre-eclampsia is to deliver the baby. Left untreated, the condition can lead to convulsions, kidney failure and serious liver problems.
"If this is a gene responsible for pre-eclampsia in some families then it would be a nice genetic test," said study leader Dr Raghu Kalluri.
The team are now planning a large clinical trial in women to look at the effect of COMT.
