Harry Orr PhD

Dr. Orr is the Tulloch professor of genetics in the department and directs the Institute of Translational Neuroscience. His research is focused on the molecular genetics of neurodegenerative diseases, principally the autosomal dominant form of spinocerebellar ataxia (SCA1). Patients usually develop SCA1 in mid-life. They experience loss of motor coordination and develop slurred speech, spasticity, and cognitive impairment. These symptoms arise from the loss of Purkinje cells and damage to other nerve cells in the brain’s cerebellar cortex. Orr and his colleagues cloned the SCA1 gene and found that the disease is caused by the expansion of an unstable, repeated cytosine-adenine-guanine (CAG) sequence in DNA. The length of the trinucleotide repeat is associated with when symptoms develop.