by Neurologists at a memory clinic in China have diagnosed what they believe to be Alzheimer’s disease in a 19-year-oldmaking him the youngest person in the world to be diagnosed with the disease.
The teenage boy began suffering from memory loss around the age of 17, and the cognitive losses worsened over the years.
Imaging of the patient’s brain showed shrinkage of the hippocampus, which is involved in memory, and his cerebrospinal fluid suggested common markers of this most common form of dementia.
Alzheimer’s disease (AD) is often thought of as a disease of old age, yet early-onset cases, which include patients under the age of 65, account for up to 10 percent of all diagnoses.
Almost all patients under the age of 30 can have their Alzheimer’s disease explained by pathological gene mutations, which places them in the familial Alzheimer’s disease (FAD) category. The younger a person is when they receive a diagnosis, the more likely it is to be the result of a faulty gene they have inherited.
However, a genome-wide search by researchers at Capital Medical University in Beijing failed to find any of the common mutations responsible for the early onset of memory loss, nor any suspicious genes.
Before this recent diagnosis in China, the youngest patient with Alzheimer’s was 21 years old. They carried the PSEN1 gene mutation, which causes abnormal proteins to build up in the brain and form clumps of toxic plaque, a common trait of Alzheimer’s.
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Cases like this recent one in China are puzzling. None of the 19-year-old’s family had a history of Alzheimer’s or dementia, making it difficult to classify him as FAD, but the teenager also had no other illnesses, infections or head injuries that could explain his sudden cognitive decline.
Two years before he was referred to the memory clinic, the teenager began concentrating in class. Reading also became difficult and his short-term memory deteriorated. He often couldn’t remember what happened the day before and kept misplacing his things.
Ultimately, the cognitive decline became so severe that the young man was unable to finish high school, although he was still able to live independently.
A year after being referred to the memory clinic, he presented with losses in immediate memory, short delay memory at 3 minutes, and long delay memory at 30 minutes.
The patient’s full memory score was 82 percent lower than his peers, while his immediate memory score was 87 percent lower.
Long-term follow-up is needed to support the young man’s diagnosis, but his medical team say the patient “changes our understanding of the typical age of AD onset.”
“The patient had very early onset AD with no clear pathogenic mutations,” Neurologist Jianping Jia and colleagues write, “suggesting that its pathogenesis remains to be explored.”
The case study just goes to show that Alzheimer’s does not follow a single pathway and is much more complex than we thought, coming through numerous pathways with different implications.
In a statement to the South China Morning Post, the neurologists who described the patient’s case argued that future studies should focus on early-onset cases to further improve our understanding of memory loss.
“Unlocking the mysteries of young people with Alzheimer’s disease could become one of the most challenging scientific questions of the future,” they predict.
The study was published in Journal of Alzheimer’s Disease.
