'SORL1 Gene' - A New Risk Factor for Alzheimer's

In a major scientific breakthrough, U.S. scientists have discovered a gene responsible for the most common form of Alzheimer's disease, thus rendering it easier to screen, diagnose and treat the development of late-onset Alzheimer's disease, researchers claim.

According to finding reported in the journal Nature Genetics on Sunday, abnormalities in a gene called SORL1 increased the risk for the disease.

The DNA study involved 6000 volunteers primarily hailing from four ethnic groups;Caribbean-Hispanics, North Europeans, black Americans and Israeli-Arabs. Examination revealed that variants of the new gene, SORL1, were more common in people with late-onset Alzheimer's than in other people of the same age.

Further examinations revealed that Alzheimer's victims also had a strikingly low level of the SORL1 protein in the blood compared with healthy people.

While working normally, SORL1 regulates the flow of amyloid precursor protein inside nerve cells in the brain and drives the protein to a part of the cell where it is recycled.

However, abnormal SORL1 gene in-turn seems to set in motion a neurological chain of events that promotes the production of amyloid plaque in the brain. This plaque leads to the onset of Alzheimer's, the scientists explain.

On clarifying results, study co-author Dr. Richard Mayeux, co-director of the Taub Institute for Research on Alzheimer's disease and the Aging Brain in New York City said, “Not all people with the faulty SORL1 gene will develop Alzheimer's”.

"There are multiple genes and maybe some environmental factors involved, and it may be that some people carry a risk gene but don't get the disease," he explained. "So, until we map out all of (the) genes involved we're not going to understand exactly how to calculate risk for this disease," he said.

About Alzheimer's disease

Alzheimer's disease is a neuro-degenerative disease characterized by gradually increasing cognitive deterioration combined with declining activities of daily living and neuropsychiatric symptoms or behavioral changes.

The usual first symptom noticed is short term memory loss which gradually progresses from seemingly simple and often fluctuating forgetfulness.

Other symptoms include outbursts of violence, deterioration of musculature and mobility, inability to feed oneself.

Stages

• Mild: At the early stage of the disease, patients have a tendency to become less energetic or spontaneous, though changes in their behavior often go unnoticed even by the patients' immediate family.

• Moderate: As the disease progresses to the middle stage, the patient might still be able to perform tasks independently, but may need assistance with more complicated activities.

• Severe: As the disease progresses from the middle to late stage, the patient will undoubtedly not be able to perform even the simplest of tasks on their own and will need constant supervision. They may even lose the ability to walk or eat without assistance.

There is no known cure for Alzheimer's. It causes irreversible loss of brain function and memory. The disease affects 25 million people worldwide and the number is increasing day by day as populations is increasing. It has been estimated that by the mid-century the number could raise up to 100 million people worldwide.