The world's youngest patient with Alzheimer's probable diagnosis is a teenager from China. The 19-year-old, who is thought to be from Beijing, had been exhibiting symptoms, such as memory loss, difficulty concentrating, delayed reactions, and reading difficulties for two years.

He was forced to withdraw from his senior year of high school because, by the time he saw doctors at the Capital Medical University in Beijing, he could not even recall what he had eaten for dinner the night before.

His hypothalamus, a part of the brain that is involved in cognition, had shrunk, according to tests and scans. Additionally, he displayed Alzheimer's-related symptoms like tau protein elevation and temporal lobe damage.

The absence of any genetic mutation typically found in very young Alzheimer's patients and the lack of a family history perplexed the medical professionals who published the case report last month.

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Presenilin 1, Presenilin 2, and Amyloid precursor protein are three of the genetic mutations that can lead to an early-onset Alzheimer's diagnosis. The toxic protein fragment known as amyloid-beta peptide, a precursor to the amyloid plaques that are a hallmark of Alzheimer's disease, is produced excessively as a result of these mutations.

Doctors said, "This is the youngest case ever reported to meet the diagnostic criteria for probable [Alzheimer’s disease] without recognized genetic mutations."

Studies show that people 65 and older are most commonly affected by Alzheimer's disease. Approximately 5-10% of all Alzheimer's cases are diagnosed before the age of 65.

Previously, the youngest patient to be diagnosed was a 21-year-old, who had a genetic mutation. In another case, a 24-year-old British male was also diagnosed with the disease.

'Significant impariment' 

The Beijing team's research builds on a growing body of research into quicker diagnostics that can spot warning signs of the illness years before symptoms appear. The findings of the researchers challenge the norm that Alzheimer's affects only the elderly. They said, "[The study] proposed to pay attention to the early-onset Alzheimer’s disease."

"Exploring the mysteries of young people with Alzheimer’s disease may become one of the most challenging scientific questions of the future." The case study was published in the Journal of Alzheimer’s Disease on January 31.

The risk involved in performing a brain biopsy prevented the researchers from doing so, but they were still able to run a number of diagnostic tests to find the man's disease's biomarkers, according to the research team.

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In a series of cognitive tests, the patient was required to listen to a list of words and repeat them after a brief or extended delay. They came to the conclusion that his memory loss was "significant".

Additional brain imaging revealed that his hippocampus, which is in charge of memory function, was atrophied. The accumulation of tau protein inside neurons and the formation of plaques in the brain brought on by Alzheimer's disease are the two main causes of hippocampal atrophy, according to conventional wisdom.

On another note, there are between six and seven million Americans who suffer from Alzheimer's disease, the most prevalent type of dementia. Chronic and getting worse over time, the illness typically takes people's lives three to 11 years after being diagnosed. However, preclinical Alzheimer's disease, as it is known by researchers, is a stage of the disease where symptoms can be absent for years. Anyone cannot see symptoms during this phase, which can last for decades.