n engl j med
yielded important new biologic
insights for at least four common
diseases or polygenic traits — and
that efforts to develop new and
improved treatments and preven-
tive measures on the basis of these
insights will be well under way.
Dr. Hirschhorn reports receiving consult-
ing fees from Correlagen and Ipsen, having
an equity interest in Correlagen, receiving lec-
ture fees from Pfizer, and receiving grant
support from Novartis. No other potential
conflict of interest relevant to this article
This article (10.1056/NEJMp0808934) was
published at NEJM.org on April 15, 2009.
Dr. Hirschhorn is an associate professor in
the Program in Genomics and the Divisions
of Genetics and Endocrinology, Children’s
Hospital, Boston; an associate professor of
genetics at Harvard Medical School, Bos-
ton; and an associate member and coordi-
nator of the Metabolism Initiative at the
Broad Institute of Harvard and MIT, Cam-
Altshuler D, Daly MJ, Lander ES. Genetic
mapping in human disease. Science 2008;
Mohlke KL, Boehnke M, Abecasis GR.
Metabolic and cardiovascular traits: an abun-
dance of recently identified common genetic
variants. Hum Mol Genet 2008;17:R102-
Lettre G, Rioux JD. Autoimmune diseases:
insights from genome-wide association stud-
ies. Hum Mol Genet 2008;17:R116-R121.
Hirschhorn JN, Lettre G. Progress in ge-
nome-wide association studies of human
height. Horm Res (in press).
Styrkarsdottir U, Halldorsson BV, Gretars-
dottir S, et al. Multiple genetic loci for bone
mineral density and fractures. N Engl J Med
Copyright © 2009 Massachusetts Medical Society.
Genomewide Association Studies — Illuminating Biologic Pathways
Genetic Risk Prediction — Are We There Yet?
Peter Kraft, Ph.D., and David J. Hunter, M.B., B.S., Sc.D., M.P.H.
major goal of the Human
Genome Project was to facili-
tate the identification of inherit-
ed genetic variants that increase
or decrease the risk of complex
diseases. The completion of the
International HapMap Project and
the development of new methods
for genotyping individual DNA
samples at 500,000 or more loci
have led to a wave of discoveries
through genomewide association
studies. These analyses have iden-
tified common genetic variants
that are associated with the risk
of more than 40 diseases and hu-
man phenotypes. Several compa-
nies have begun offering direct-
to-consumer testing that uses the
same single-nucleotide polymor-
phism chips that are used in
genomewide association studies.
These companies claim that such
testing should be made available
to consumers who are interested
in their personal level of risk for
the relevant diseases. Now, “risk
tests” for specific diseases such
as breast cancer are also being
marketed to physicians and con-