Last year, neurologists in a Chinese memory clinic diagnosed a 19-year-old with what they believed to be Alzheimer’s disease, marking him as the youngest known case of the condition.
The teenager began showing signs of memory decline around the age of 17, and his symptoms progressively got worse.
Brain scans indicated shrinkage in the hippocampus, a crucial area for memory, and his cerebrospinal fluid displayed biomarkers typically associated with Alzheimer’s, the most prevalent form of dementia.
While Alzheimer’s is generally linked to older individuals, early-onset cases—those diagnosed in people under 65—make up about 10 percent of all diagnoses.
Typically, patients with Alzheimer’s under 30 can attribute their condition to genetic mutations, a classification known as familial Alzheimer’s disease (FAD).
The younger a patient is at diagnosis, the greater the likelihood that an inherited mutation is to blame.
However, researchers from Beijing’s Capital Medical University could not identify any of the usual mutations linked to early Alzheimer’s onset during a comprehensive genetic investigation.
“This case represents the youngest recorded instance meeting the criteria for probable Alzheimer’s without known genetic mutations,” said neurologist Jianping Jia and his team in their research.
Prior to this situation in China, the youngest Alzheimer’s patient documented was 21 and had the PSEN1 gene mutation, known for causing harmful protein buildups in the brain, which are often seen in Alzheimer’s.
Cases like this one present a conundrum.
None of the 19-year-old’s family had a history of Alzheimer’s, complicating its classification as familial. But, on the other hand, there were no other health issues, infections, or head trauma that could explain his cognitive decline.
About two years before being sent to the memory clinic, the teenager found it hard to concentrate in class and reading became challenging. His short-term memory faltered as well.
Often, he couldn’t recall events from the previous day, and he frequently misplaced items.
Ultimately, his cognitive decline intensified to the point where he was unable to complete high school, although he managed to live independently.
A year after being referred, tests showed significant short-term memory deficits; his immediate recall and even delayed recall after three minutes left much to be desired.
His overall memory score was remarkably 82 percent lower than that of his peers, with immediate memory 87 percent lower.
Long-term follow-up is essential to validate the diagnosis, yet his medical team remarked that this case was “changing our understanding of Alzheimer’s disease onset age.”
“The patient exhibited very early-onset Alzheimer’s with no clear pathogenic mutations,” the researchers stated, underscoring the need for deeper investigations into its origins.
This case study, released in February 2023, highlights how Alzheimer’s does not follow a single trajectory and is more intricate than previously realized, developing through various channels with diverse impacts.
In a statement to the South China Morning Post, the neurologists behind the patient’s case suggested that further research on early-onset cases could enhance our understanding of memory loss.
“Investigating the enigmas surrounding young Alzheimer’s patients may become one of tomorrow’s most formidable scientific challenges,” they added.
The study appeared in the Journal of Alzheimer’s Disease.
