Alzheimer’s disease does run in some families, particularly in early-onset cases in which someone gets the disease well before the age of 65. Fortunately, these devastating cases represent less than 5 percent of all diagnoses, and you get your genes from your parents. They come grouped in long strands of DNA called chromosomes. Every healthy person is born with 46 chromosomes in 23 pairs. Usually, you get one chromosome in each pair from each parent. In many conditions, having Alzheimer's disease in the family does very slightly increase the chance of people in later generations getting the disease. The Alzheimer’s Association states that Alzheimer’s disease is the sixth leading cause of death and for most people, the disease has genetic, lifestyle, and environmental factors. All these factors may work together to create the right conditions for the disease to take root. There is a hereditary component to Alzheimer’s. People whose parents or siblings have the disease are at a slightly higher risk of developing the condition. However, we’re still a long way from understanding the genetic mutations that lead to the actual development of the disease. Alzheimer's disease is an irreversible, progressive brain disease.