GENE THERAPY: DNA Editing Patent Granted - Brief Article

Applied Genetics News, April, 2000

Enzo Biochem, Inc. (60 Executive Blvd., Farmingdale, NY 11735; Tel: 516/755- 5500, Fax: 516/755-5569) has been granted a U.S. Patent 5,958,681 for a method of nucleic acid sequence editing. The patent claims a method and materials suitable for correcting point mutations or small insertions or deletions of genetic material. For example, genetic abnormalities caused by single nucleotide alterations or small deletions could be corrected through the insertion or exchange of the correct or desired sequences into the genome of the cell where the error exists. This gene editing technique differs from other gene therapies that require the insertion of an entire new gene to correct a nonfunctional or incorrectly functional gene.

The gene editing method works by correcting the specific gene within cells with defined short gene sequences. These sequences are held in place through formation of a triple helix complex. When the short gene sequence containing the correct sequence is held in close proximity to the target DNA to be corrected, the probability of a double crossover or an editing event becomes quite high. The triple helix holds the sequences in close proximity and at a precise point in the gene long enough for recombination, exchange or insertion to take place with a high frequency.

"The patent provides Enzo with a commanding position to pursue what appears to be a highly promising new genetic correcting mechanism," says Dean L. Engelhardt, senior vice president of Enzo.