Huntington’s disease is an inherited, progressive neurologic disease for which there is no treatment or cure. Symptoms, which include deterioration of muscle control, cognition and memory, develop between 35 and 44 years of age, but can start earlier. HD is usually fatal within 10 to 20 years after the onset of symptoms. The disease has a high prevalence for an inherited disorder, affecting approximately 30,000 people (one in 10,000) in the US. An additional 150,000 people in the US carry a 50% risk of developing the disease.
HD is caused by a particular type of mutation in a single gene, the Huntingtin (Htt) gene, which encodes a protein of the same name. This mutation is present in all Huntington’s patients and is characterized by an expansion of a repeated stretch of DNA sequence within the gene. The normal Htt gene has up to 28 copies of this so-called “CAG-repeat” but individuals with Huntington’s disease have many more – generally greater than 40 CAG-repeats. The greater the number of repeats the earlier the symptoms appear and the faster disease progresses. Most patients inherit one normal and one defective copy of the Htt gene, and just one copy of the faulty gene is enough to cause HD.
Our therapeutic strategy is to lower the levels of the disease-causing form of Htt while preserving levels of normal protein. We are developing ZFP Therapeutic approaches to Huntington's disease in partnership with Shire AG.