The Texas Institute for Genomic Medicine announced today that researchers
associated with the Institute and Lexicon Genetics Incorporated (Nasdaq:  LEXG)
have discovered that defects in the FKBP8 gene may play a role in spina bifida,
a common birth defect affecting the lower spinal column. Richard H. Finnell, Ph.D.,
interim director and president of the Texas Institute for Genomic Medicine, presented
this finding at the Fourth International Workshop on Neural Tube Defects on
Saturday, September 10, 2005 in Palm Springs, California. Dr. Finnell's
presentation is entitled "FKBP8 - A new mouse model of spina bifida."

There are approximately 70,000 people in the United States living with spina
bifida, the most common permanently disabling birth defect. Spina bifida is a
neural tube defect that occurs in the first month of pregnancy when the spinal
column does not close completely. It can result in full or partial paralysis of
the legs and lower body, bladder and bowel control difficulties, learning
disabilities and depression. At present, the primary means of preventing this
birth defect is through maternal dietary supplementation with multivitamins
containing folic acid.

"This finding has the potential to lead to the prevention of spina bifida and
improve the quality of life for the many thousands of people living with this
debilitating disease," said Dr. Finnell. "It is just one example of the ability
of the OmniBank library of mouse embryonic stem cell clones to illuminate the
functions of genes. We believe that researchers accessing this valuable resource
through the Texas Institute for Genomic Medicine will accelerate the pace of
scientific discoveries related to human healthcare."

Through the creation of mice with an altered FKBP8 gene that functions at
reduced levels, scientists have discovered a model for spina bifida that could
provide new insight into the human disease. Existing disease models focus on
folic acid and the folate pathway genes. This new model demonstrates 100-percent
penetrant lesions comparable to the human form of the disease. As a result, it
is expected to improve understanding of the gene pathways involved in normal and
abnormal neural tube closures, with the goal of ultimately preventing and
treating spina bifida. Researchers at the Institute for Genomic Medicine are
beginning to screen human DNA samples for occurrence of this gene defect in
order to correlate their findings with spina bifida in the human population.

The Texas Institute for Genomic Medicine is a non-profit institute created under
an award from the Texas Enterprise Fund to pioneer the development of
life-changing medical breakthroughs, accelerate the pace of medical discoveries
and foster the development of the biotechnology industry in Texas. Using its
patented gene knockout technologies, Lexicon Genetics is creating for the
Institute a comprehensive knockout mouse embryonic stem cell library containing
350,000 cell lines. When complete, the new library is expected to be the world's
largest collection of mouse embryonic stem cells that have been engineered for
the study of gene function, allowing researchers to identify genes that could
lead to advancements in human healthcare. The Institute will make cells from its
library available to researchers worldwide. It is based in Houston at the Texas
A&M University System Health Science Center's Institute of Biosciences and
Technology and in College Station at Texas A&M University.