GENOMICS

Murky associations

(2009)

Genome-wide association studies have

been hailed for their ability to find genetic

variations that may contribute to disease risk.

But assigning meaning to these variations is

more difficult. Peter Holmans of the MRC

Centre for Neuropsychiatric Genetics and

Genomics in Cardiff, UK, and his colleagues

have developed an approach that they call

ALIGATOR.

They look for gene ontology categories

— agreed-upon terms used to define the

function and activity of gene products — that

regularly pop up in the candidates exposed

by genome-wide association, reasoning

that many associations in the same category

signal functional relevance. For Crohn’s

disease, which is immunological in origin,

overrepresented ontological categories

included immune functions, as expected.

For bipolar disorder, they included hormone

activity and RNA splicing, processes with as

yet unknown roles in the condition.