HB, or Huntington's disease, is a genetic disorder that affects the brain, leading to progressive degeneration of nerve cells. It is caused by a mutation in the HTT gene, which produces a protein called huntingtin. Symptoms typically appear in mid-adulthood and can include movement disorders, cognitive decline, and emotional disturbances. The disease is inherited in an autosomal dominant pattern, meaning that a person only needs one copy of the mutated gene from a parent to develop the condition. Currently, there is no cure for HB, but treatments are available to help manage symptoms and improve quality of life for those affected.