Globoid Cell Leukodystrophy (Terrier Type) is an inherited Lysosomal Storage Disorder affecting West Highland White Terriers. Affected dogs are normal at birth but at about 6 to 22 weeks of age, these dogs show signs of muscle weakness and uncoordinated movement. Affected dogs have a deficiency of the Enzyme galactocerebrosidase which is responsible for breaking down Myelin in the nervous system. As a result, there are abnormal accumulations of fatty myelin bi-products that affect the ability of certain nervous cells to make myelin. Symptoms include crossing legs while walking, widely spaced stance, jerky movements, high stepping and body tremors. Overall muscle tone is decreased and reflexes are decreased or absent. As the disease progresses, blindness, paralysis and death can occur.