Fragile X syndrome, a dominant X-linked disease, affects approximately 1 in 2,500 individuals and is a prevalent cause of inherited neurological disorders causing mental retardation (Kaufmann and Reiss 1999).  A single mutated gene has been identified, FMR1, and defined as the cause of Fragile X.  The  Fragile X site is highly polymorphic in the chromosomes of Fragile X individuals and contains long CGG repeats.  This CGG polymorphism has been identified as the cause of DNA instability (Kremer et al.  1991).  Genetic instability caused when the mutation results in an increase in the copy number of trinucleotides is called an expansion mutation (McMurray 1995).  Expansion is the process in which there is unstable transmission of repeating units.  In Fragile X, expansion causes disease when the trinucleotide CGG is repeated >200 times.  This is beyond the normal copy number of 6-25.  The expanded repeat causes disease...