Scientists have discovered that the gene SORL1 - the fifth gene to be linked to Alzheimer's - can identify whether a person may develop Alzheimer's disease in their later years. SORL1 and ApoE4 are the only two genes that have been identified to have abnormalities on people with late-onset Alzheimer's.

Although the time span between discoveries is daunting (ApoE4 was discovered in 1993, SORL1 was discovered early 2007), it's still a good step toward preventive medicine. Now scientists have one more ace up their sleeve to find out how they can prevent the disease that plagues a good portion of older folk.