A team of scientists at Washington University School of Medicine has been able to chart out the way the Alzheimer’s disease progresses, before the symptoms can be diagnosed. The scientists considered those families, in which there were high chances of developing the disease due to hereditary reasons.

The study included 128 people from UK, US and Australia. Researchers said, “These people had a 50% chance of inheriting one of three mutations that are certain to cause early Alzheimer's, which often develops in people's 30s and 40s”.

However, the most common form of the disease is administered at the age of 60s. Further, the experts explained that those people, who were carrying the mutation, developed the disease. The researchers then took into consideration age of volunteer’s parents at which they developed the disease.

They carried out several blood and spinal tests and also brain scans and evaluated the mental levels of the patients. They suggested that lowering of spinal fluid levels was foremost symptom of the disease, raised levels of tau protein and shrinkage of parts of brain are other symptoms to be administered at the age of 15 years.

The study published in the New England Journal of Medicine, suggests that the symptoms of the disease start emerging almost 25 years before the commencement of the disease.