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.
About younger-onset Alzheimerâs. Alzheimerâs disease is considered to be younger-onset Alzheimerâs if it affects a person under 65. Younger-onset can also be referred to as early-onset Alzheimerâs.People with younger-onset Alzheimerâs can be in the early, middle or late stage of the disease.After a younger-onset diagnosis, individuals can live meaningful and productive lives. You still have much to contribute to the world.bout younger-onset Alzheimerâs. Alzheimerâs disease is considered to be younger-onset Alzheimerâs if it affects a person under 65. Younger-onset can also be referred to as early-onset Alzheimerâs.