Summary
Researchers at the University Nebraska Medical Center have
developed a sensitive and quantitative assay for the screening of
trinucleotide repeat (TNR) mutations. The assay system involves the
transfer of a DNA shuttle vector between mammalian and yeast
cells. TNR mutations generated during mammalian cell culture are
revealed by transfer of the vector to yeast followed by genetic
analysis. Expansions of specific DNA trinucleotide repeats (TNR) are
the cause of an increasing number of hereditary disorders in
humans. Specifically, the pathological expansion of unstable
repeats is known to cause 14 neurological diseases. In some
diseases, such as Huntington's, the repetitive DNA sequences are
translated into long tracts of the same amino acid (usually
glutamine), which alters interactions with cellular constituents and
leads to the development of disease. For other disorders, including
common genetic disorders such as myotonic dystrophy and fragile
X syndrome, the DNA repeat is located in noncoding regions of
transcribed sequences and disease is probably caused by altered
gene expression. The diagnosis of these diseases can be made by
detection of the TNR known to be associated with the disease.
However, further advances in risk assessment for, diagnosis of, and
development of potential therapies for these diseases will be greatly
facilitated by selective, genetic assays for TNR mutations. Current
methods for detection of TNR and subsequent diagnosis of disease
are non-selective and non-quantitative. The major advantage of this
technology is to provide a selective and quantitative genetic means
to measure expansions and contractions of trinucleotide repeat
tracts. This advantage allows its application to the field of
predictive toxicology.
The ongoing development of the assay will enable its use as a
means of assessing the risk of TNR mutations that is associated with
a particular compound. Importantly, the selective and quantitative
aspects of this assay system will also enable its further development
as a mechanism for screening compounds, agents or small
molecules, which are directed at inhibiting further expansion (or
stimulating contraction) of TNR regions that are associated with
disease.

Market Value
The discovery of the underlying mechanisms for TNR mutations is
vital to the development of treatments for diseases such as
Huntington's or Fragile X Syndrome. This genetic assay uses human
cells culture and yeast selective plating techniques to identify
elements that influence the genetic stability of TNR sequences, and
the discovery of agents that could be developed as therapeutics for
treating TNR determined diseases.

Features and Benefits
• Works with human cell cultures
• Identifies expansion or contraction mutations

Patent Issued (TID - 99)

UNeMed Corporation offers a variety of licensing options and collaborative development opportunities with the University of Nebraska Medical Center.