In this article, it discusses Alzheimer's disease and how it is caused. Alzheimer's is a disease many people suffer from relatively old ages, usually over the age of 65. It is a degenerative disease of the brain, a gradual loss of memory, judgment, and ability to function come with being affected. Memory loss is said to be the number one sign of this disease. The loss of memory continuously becomes worse over time until it interferes with most aspects of daily living. Even in familiar settings, a person may often become lost or confused. The normal routine tasks such as performing household chores become challenging without assistance. Some cases of early Alzheimers are caused by a gene mutation that can be passed from parents to their children. This is a result of early-onset familial Alzheimers disease. This disorder can result from a mutation within the APP, PSEN1 or PSEN2 genes. Those who inherit the APOE 4 allele have a higher chance of being affected by the disease.