Sun Xiaoyu, 18, poses in front of Harbin Vocational and Technical College in Heilongjiang province. [Photo provided to chinadaily.com.cn]

Earlier this month, Sun Xiaoyu began a new chapter in his life in Harbin Vocational and Technical College in Heilongjiang province.

What makes this 18-year-old freshman different from his classmates is that he will continue to take care of his grandmother and cousin while in college.

"Since the 70s, a total of seven members of my family died of Huntington's disease, including my father-in-law, my husband, my three children, my grandson and my husband's sister," said HuaXianzhen, Sun's grandmother. "My grandson has become the backbone of my family with only three of us left."

Huntington's disease is a kind of genetic disorder caused by aggregating proteins inside brain neurons that ultimately lead to motor dysfunction, personality changes, depression and dementia.

There is no known cure. Although the patient may have a long life, many die in their forties. Fortunately, Sun does not have the disease.