NIH SELECTS EMORY UNIVERSITY SCHOOL OF MEDICINE SCIENTIST FOR HALL
Institute of Child Health and Human Development Honors Dr. Stephen
T. Warren for Genetics Discoveries
ATLANTA – The National Institute of Child Health and Human Development
(NICHD) has selected Stephen T. Warren, PhD, chair and William P. Timmie
professor of human genetics at Emory University School of Medicine,
for its Hall of Honor, commemorating the Institute’s 40th anniversary.
This new award recognizes scientists supported by the NICHD for their
exceptional contributions to advancing knowledge and improving maternal
and child health.
The 15 selected scientists were honored in a ceremony on the campus
of the National Institutes of Health in Bethesda, Maryland. The scientists’
portraits and descriptions of their research contributions will be hung
in the halls of the NICHD.
Dr. Warren was honored for his identification of Triplet Repeat Expansion
as the cause of fragile X syndrome and as an entirely new inheritance
mechanism of genetic disease. In 1991 Dr. Warren led an international
research team that discovered the FMR1 gene, which is responsible for
fragile X syndrome, the most frequent inherited form of mental retardation.
In 1993 Dr. Warren’s team characterized FMRP, the protein expressed
by the normal FMR1 gene, and learned that fragile X syndrome occurs
when the FMR1 gene does not produce the FMRP protein. This results in
the abnormal translation of other genes into proteins required for neuron
Most patients affected by fragile X syndrome share a common genetic
mutation called triplet repeat expansion. All genes comprise combinations
of four chemical bases (A, C, G, and T) used to translate genetic information
to proteins. Within the normal FMR1 gene, the triple combination of
CGG is repeated only about 30 times, but in persons affected by fragile
X, the CGG combination is repeated more than 200 times. When this occurs,
the gene stops producing the FMRP protein. This protein silencing leads
to symptoms including mental retardation, attention deficit disorder
and connective tissue disorder. This unique mutational mechanism, previously
unknown in any species, was first uncovered with the discovery of FMR1
and later has been demonstrated as the mutational mechanism in over
a dozen other genetic disorders, including Huntington Disease.
Emory University has the largest NIH-funded research program on fragile
X syndrome in the world, and Emory School of Medicine scientists were
among the first to develop genetic tests to diagnose the syndrome. Just
within the past decade genetic counselors have been able to help carriers
of FMR1 predict the probability of giving birth to a child affected
by fragile X.
In the past few years Dr. Warren and his colleagues have demonstrated
that the genetic mutation leading to fragile X syndrome goes well beyond
the original protein expression of the gene and affects additional proteins
that cause "downstream" cellular consequences that could negatively
influence development and behavior. Thus far, no treatment has been
available for fragile X syndrome, but the Emory scientists believe their
new knowledge about the mechanisms of fragile X may soon enable the
development of therapeutic approaches to regulate the gene expression
and neural pathways involved.
"Dr. Warren is a shining example of a scientist who is translating outstanding
laboratory research into diagnostic tests and therapies that have the
potential of dramatically improving the lives of thousands of patients,"
said Thomas J. Lawley, MD, dean of Emory University School of Medicine.
"We take great pride in his accomplishments, and look forward to the
day when fragile X syndrome can be successfully prevented or treated."