Levene died in 1940, before the true significance of DNA became clear. Levene is known for his tetranucleotide hypothesis (formulated around 1910) which first proposed that DNA was made up of equal amounts of adenine, guanine, cytosine, and thymine.
Alzheimer's is not just a disease of old age. Younger-onset (also known as early-onset) Alzheimer's affects people younger than age 65.Up to 5 percent of the more than 5 million Americans with Alzheimerâs have younger-onset.eople who have early onset Alzheimer's may be in any stage of dementia â early stage, middle stage or late stage. The disease affects each person differently and symptoms will vary. If you are experiencing memory problems: 1  Have a comprehensive medical evaluation with a doctor who specializes in Alzheimer's disease.
Experts also estimate that up to 800,000 million adults with Alzheimer's disease live alone, and about half of those people don't have a caregiver. Life Expectancy On average, people with Alzheimer's live eight to 10 years after diagnosis, but the disease can progress over the course of two to 20 years. According to the Alzheimer's Association, one out of three older adults dies with Alzheimer's or another kind of dementia.