The French scientist who discovered the cause of Down's syndrome has taken the first step to sainthood, the Vatican said on Thursday.

Pope Francis has recognised the "heroic virtues" of Professor Jerome Lejeune, who died in 1994 aged 67, a statement said.

This clears the way for Lejeune to be beatified in the future, provided that the Vatican attributes a miracle to him.

Beatification is one step removed from sainthood, which normally comes after the attribution of a second miracle.

Jerome Lejeun became a passionate anti-abortion campaigner, working with the Vatican on the issue and becoming personal friends with Pope John Paul II
Jerome Lejeun became a passionate anti-abortion campaigner, working with the Vatican on the issue and becoming personal friends with Pope John Paul II AFP / -

In 1958, Lejeune and two other researchers discovered that Down's syndrome sufferers are born with an extra chromosome.

Down's syndrome is a genetic disorder associated with mental and physical disabilities, recorded in 23 out of every 10,000 births in the European Union in 2015.

Lejeune's research helped the prenatal detection of the disorder, sometimes leading to abortions -- something he strongly objected to.

The professor became a passionate anti-abortion campaigner, working with the Vatican on the issue and becoming personal friends with Pope John Paul II, who was recently made a saint.

A foundation in his name now supports research and treatment for genetic intelligence disorders, and is engaged in anti-abortion advocacy.