Written by Ashley Nee, ‘22
Edited by Jess Seveston
Since its discovery by Alois Alzheimer in 1906, Alzheimer’s disease (AD) has frustrated scientists and physicians alike. The cause of this memory-robbing illness as well as the development of a therapeutic treatment to either stop or reverse its effects remain elusive.  Several hypotheses point to or include genetic differences as a part of the disease etiology. A recent study implicates five new genomic loci in causing AD.  Published in Nature Genetics, it is the largest of any investigation into the genetic factors underlying AD.
In order to generate a large study population, the scientists behind the study from Nature Genetics turned to the International Genomics of Alzheimer’s Disease Project . The project ran a series of genomic wide association studies (GWAS), a type of database that compares genetic variants among a pool of different people to determine if a genetic variant is associated with a trait.  Thus, examination of these GWASs by the authors of the Nature Genetics study allowed for the identification of five new genome wide loci linked to AD: IQCK, ACE, ADAM10, ADAMTS1, and WWOX. 
It is important to note that these loci do not refer to specific genes, rather they refer to locations on chromosomes. Therefore, in order to identify functional genes related to AD, eight different variables -- all established in previous literature as being connected to AD -- were used to rank genes near the five identified loci by the likelihood of their association to AD. 
While this methodology of GWAS analysis and subsequent ranking is beneficial in identifying new genes linked to AD, the study remains limited, mainly because its population is largely white. John Hardy, one of the co-authors of the study, also commented on the overall lack of “GWAS in African and Asian populations.”  Such limitations in diversity are a problematic yet all too common issue in research. Hopefully, recognition of this problem may lead to future GWAS with greater diversity.  In spite of this current limitation, the study from Nature Genetics provides new and interesting options for scientists to explore in the fight against AD.