Sang Zixuan is 7 years old and his brother Sang Ziheng is 6 - yet they look like old men.

The children suffer a rare early-aging condition, or progeria, that none of the doctors who visited their family at a village of Luyi county in Henan province could diagnose or treat, said their grandfather Sang Fayu.

Both looked like normal children in their first year. Sang Zixuan was plump and healthy when he was born, and Sang Ziheng could speak a few simple words by the time he was 1 year old.

Sang Zixuan and Sang Ziheng, 7 and 6 years old, suffer from progeria, a rare early-aging condition, at a village of Luyi county in Henan province. Ma Zhiwei / For China Daily

But in their second year, things changed. The boys developed skin conditions, their bones became fragile and they lost the ability to speak.

The family took the children to many medical agencies nationwide, including some of the most advanced hospitals in Henan and Northeast China's Heilongjiang province, but none could treat the rare disease.

"The doctors just gave my grandchildren some physical checks, and they could not prescribe any medicine for the symptoms," Sang told China Daily. The children's parents have spent almost 600,000 yuan ($95,000), mostly borrowed from relatives after their savings ran out, seeking medical treatment.

Their parents started working recently on a construction site in Tianjin in order to afford the medical expenses, while the boys live with their grandparents.

Sang Fayu told local media last week that the family is willing to send either child to take part in clinical drug trials at any hospital or center that would care to research progeria, in the hope of developing a cure or effective treatment.

There have been other cases of early aging reported in China.

The son and daughter of a couple in Anhui province were found to have progeria at the age of one, and the children died when they were 15 and 17, according to a 1986 report in the China Health Pictorial, a magazine sponsored by the Ministry of Health.

It was believed the progeria might have been a consequence of the parents being blood relatives.

However, grandpa Sang Fayu said that his son and daughter-in-law were not related by blood and he disputed that progeria was a hereditary condition.

Children with progeria in other nations include Hayley Okines, a 14-year-old girl in the United Kingdom. She remains active and in high spirits, and wrote her autobiography, Old Before My Time, last year.

Another case is Seth Cook, from Washington state in the United States who died at home, aged 13, from a heart attack in 2007.

The Progeria Research Foundation, a non-profit organization established in 1999 dedicated to finding treatments and a cure, said on its website that there are 89 children known to be living with the aging disorder in 39 countries.

There is still no definitive test for the disease, said the foundation, which is based in Massachusetts.

Ma Rui and Yu Yang contributed to this story.

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