13 new rare gene variants of Alzheimer's identified

In a first-of-its-kind study to use whole-genome sequencing (WGS), scientists have discovered about 13 new rare genomic variants or mutations associated with Alzheimer's disease (AD).

Researchers at Massachusetts General Hospital (MGH) who reported the findings of the study said that these lesser-known gene mutations may hold critical information about the biology of the disease and can help in the development process of new drugs for the devastating neurological condition.

The study was published in Alzheimer's & Dementia: The Journal of the Alzheimer's Association.

"Rare gene variants are the dark matter of the human genome and there are lots of them: Of the three billion pairs of nucleotide bases that form a complete set of DNA, each person has 50 to 60 million gene variants and 77 per cent are rare," said Tanzi, one of the researchers.

The researchers performed whole-genome sequencing on the genomes of 2,247 individuals from 605 families that include multiple members who have been diagnosed with AD. They also analyzed WGS datasets on 1,669 unrelated individuals.

The study found that these new gene variants have a link with the development of neurons, the functioning of synapses, which are the junctions that transmit information between neurons and also neuroplasticity, which is the ability of neurons to reorganize the brain's neural network.

According to scientists, it is important to identify and study the less-common gene mutations that increase the risk for AD as it may hold critical information about the biology and nature of the disease and what can be done to treat it.

"This paper brings us to the next stage of disease-gene discovery by allowing us to look at the entire sequence of the human genome and assess the rare genomic variants, which we couldn't do before," said lead author Dmitry Prokopenko from MGH's McCance Center for Brain Health.