All diseases are awful, but Alzheimer's is arguably the most feared. Millions have been affected by Alzheimer's, but a new gene test might offer some hope.

International researchers think they've developed a gene test that will assess a person's genetic risk of developing Alzheimer's disease by a given age. This tool could lead to faster diagnosis and treatment.

The test was developed using 70,000 Alzheimer's patients and elderly people without the disease across the world.

Alzheimer's is usually first detected in a person's 60s, but rare cases can start as early as the 30s. Some 45 million people are living with Alzheimer's. There's no cure and no effective treatment.

"We can calculate your 'personalized' annualized risk for developing Alzheimer's disease," said Rahul Desikan, one of the authors of the medical report.

He says more research is needed before an effective test can be made publicly available.