A cruel twist of genetic fate brought Alzheimer’s disease to a sprawling Colombian family. But thanks to a second twist, one member of the clan, a woman, managed to evade the symptoms for decades.
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The woman in the afflicted family who somehow fended off the disease carried the same mutation that usually guarantees dementia. And her brain was filled with plaques formed by a sticky protein called amyloid. Many scientists view that accumulation as one of the earliest signs of the disease. Yet she stayed sharp until her 70s.
Researchers were stumped, until they discovered that the woman also carried another, extremely rare genetic mutation that seemed to be protecting her from the effects of the first one. This second mutation, in a different Alzheimer’s-related gene called APOE, seemed to slow the disease down by decades.
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Although the discovery is based on one person, it points to a biological weak spot in the degenerative disease that affects an estimated 5.8 million people in the United States alone. So far, nearly every clinical trial designed to slow or stop the disease has failed.
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Perhaps this unusually resilient woman in Colombia shows a way to halt the disease, or at least slow it down.
