MILAN: Sammy Basso, who was the longest-living survivor of the rare genetic disease progeria, has died at the age of 28, the Italian Progeria Association said on Sunday (Oct 6).

Progeria, also known as Hutchinson–Gilford syndrome (HGPS), causes people to age rapidly, leading them to appear older than they are, with a reduced quality of life and a life expectancy of only 13.5 years without treatment, the association's website said.

It affects one in every 8 million people born, and has a worldwide incidence of one in every 20 million.

Born in 1995 in Schio, in the northern Italian region of Veneto, Basso was diagnosed with progeria at the age of two. In 2005, he and his parents founded the Italian Progeria Association.

He became famous through the National Geographic documentary Sammy's Journey, which recounts his journey along Route 66 in the United States, from Chicago to Los Angeles, with his parents and one of his best friends, Riccardo.

"Today our light, our guide, has gone out. Thank you Sammy for making us part of this wonderful life," the association wrote on its Instagram page.

There are only 130 recognised cases of classic progeria worldwide, of which four are in Italy.

However, the Italian Progeria Association estimated there could be as many as 350 cases as they can be difficult to trace especially in developing countries.