About the Freudenreich Lab
My lab uses the yeast, Saccharomyces cerevisiae (baker's yeast) as a model organism to study how genome instability contributes to human genetic disease.
The majority of inherited genetic diseases are caused by point mutations in DNA. However, in 1991, a new type of mutation was discovered: the expansion of trinucleotide repeat sequences. This type of mutation, expansion of a repetitive DNA sequence, is the cause of a number of inherited diseases. Some examples include Huntington's disease (a degenerative neurological disease), Fragile X syndrome (the most common inherited mental retardation), and myotonic dystrophy (a type of muscular dystrophy).
The mechanism of trinucleotide repeat instability is interesting both for understanding the origin of the triplet repeat diseases and for a basic understanding of genome stability and how repair and replication occur within repetitive DNA. The timing and mechanism of expansion are important for understanding how triplet diseases are inherited as well as for predicting disease development during an individual's lifetime. In addition, some expanded repeats, including CTG/CAG sequences, are sites of chromosome fragility, areas prone to breakage in vivo. Chromosome breakage is implicated in the generation of translocations and deletions found in many types of cancer.