The role of genetics in alzheimer’s disease

Alzheimer's disease is a progressive neurological disorder that causes the brain to shrink (atrophy) and brain cells die. Alzheimer's disease is the most common cause of dementia and causes a decrease in thinking skills and social behaviors. Alzheimer's disease is more common in people over 65 years old. The risk of developing Alzheimer's disease and other types of dementia increases with age, and it is estimated that 1 in 14 people over the age of 65 and 1 in 6 people over the age of 80 will develop it. But about 1 in 20 people with Alzheimer's are under 65 years old. This is called early-onset or young-onset Alzheimer's disease. Approximately 5.8 million people in the United States age 65 and older are living with Alzheimer's disease. Of these, 80 percent are 75 years old and older. Of the approximately 50 million people with dementia worldwide, between 60 and 70 percent have Alzheimer's disease. Alzheimer's disease is a progressive and neurodegenerative disease. The two main forms of this disease are early-onset (familial) and late-onset (disseminated) disease. Which is very rare and accounts for less than 5% of patients and is inherited in a Mendelian dominant manner and is caused by mutations in three APP, PSEN1 and PSEN2 genes. A late-onset disease that is common among people over 65 years of age. The heritability of this form of the disease is high (79%), and is caused by a combination of genetic and environmental factors. A large number of genes are involved in the development of late-onset Alzheimer's disease. Examples that have been confirmed by multiple studies include ABCA7, APOE, BIN1, CD2AP, CD33, CLU, CR1, EPHA1, MS4A4A/MS4A4E/MS4A6E, PICALM, and SORL1. Finding the remaining genetic factors involved in the development of late-onset Alzheimer's disease has the potential to provide new targets for treatment and prevention, leading to the development of effective strategies to combat this devastating disease.