The aim of this study is to investigate whether stem cells from donated umbilical cord blood can improve the degenerative effects of Hereditary Cerebellar Ataxia, an inherited genetic disease affecting speech and motor function. In this study the progress of two groups of 10 patients will be compared. The first group (the interventional group) will receive a transplant of donated umbilical cord blood. The second group (control group) will receive conventional therapy only. The study commenced in September 2012 and is being conducted at the Chinese Armed Police General Hospital in Beijing.