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.
Most people who get some form of dementia or Alzheimerâs disease are in their late 60s to early 70s. Early onset dementia occurs in adults as young as fifty. The Alzheimerâs Association states that the number of people 65 years old will double to 88.5 million people by 2050!However, there is no magic number or age when dementia or Alzheimerâs disease strikes.ost people who get some form of dementia or Alzheimerâs disease are in their late 60s to early 70s. Early onset dementia occurs in adults as young as fifty. The Alzheimerâs Association states that the number of people 65 years old will double to 88.5 million people by 2050!