6 April 2012. Two papers published this month claim to identify
those at greatest risk for Alzheimer’s disease and illuminate
the mechanisms behind it. In one, French researchers identify a
gene that may be poised to join the ranks of the few that are
blamed for early-onset AD. Mutations in SORL1, which has
previously been implicated in late-onset forms of the disease
(see ARF related news story) showed up in seven out of 29
families who had early-onset AD with no known genetic mutation,
according to a Molecular Psychiatry paper published April 3. A
paper published April 6 in the American Journal of Human
Genetics by U.S. researchers aims to connect some of the most
prominent AD risk alleles according to their past natural
selection. It suggests that a protective module incorporating
three of those alleles may have been beneficial in human
ancestry. Dominique Campion of INSERM in Rouen and colleagues
have long sought genes responsible for familial, early-onset AD.
Many cases of this form of AD are not caused