Dutch scientists at Leiden University’s medical centre have discovered the genetic variation which protects against type 1 diabetes, bringing a cure for the disease a step closer.

The discovery, published in the medical journal Cell, will lead to a more precise diagnosis and make it easier to predict the development of the disease. Type 1 diabetes is largely hereditary, with the immune system attacking insulin-producing cells. Sufferers have to take the hormone for the rest of their lives.

The identification of the genetic variation involved also opens the door to a possible cure through a new genome editing technique treatment called Crispr-cas in which other pieces replace pieces of DNA material.

The discovery was made by researcher Bart Roep who has been delving into the causes of diabetes for over 30 years. His former PhD René van Tienhoven came across the variant while digging through genetic data.

“One piece looked familiar,” he told broadcaster NOS. “I thought, that’s interesting. I had no idea it was something major until Bart started jumping for joy when I showed it to him,” Van Tienhoven said.

Roep said the discovery is his “crowning achievement” and an important step in the search for a cure for the condition which affects 100,000 people in the Netherlands.

Roep and his team are also investigating if the discovery of the genetic variant can help explain why some treatments work in some and not in others. If that turns out to be the case, treatment can become more geared towards the specific needs of the individual, he said.