Gemma Illingworth, from Manchester, was just 28 when she was diagnosed with posterior cortical atrophy (PCA) — a rare, visual form of Alzheimer’s disease that affects spatial awareness, vision, and cognitive processing.

At first, her family believed she simply needed more support. Her siblings, Ben and Jess, noted that Gemma had always seemed a bit “ditsy,” and the early symptoms—blurred vision, trouble reading, and difficulty with light sensitivity—were subtle. But during the 2021 lockdown, her vision worsened, and she had to leave work. A scan revealed PCA.

As her condition progressed, Gemma lost the ability to walk, talk, see, and swallow. She passed away in November 2024 at just 31.

“She didn’t show the tell-tale signs,” said Jess. “We never imagined she had such a horrendous disease.”

To honor her memory and raise awareness, her siblings ran the London Marathon, supporting Rare Dementia Support. “They helped us navigate it the best way we could,” said Ben.

PCA has no cure—but through awareness and funding, families hope no one else faces it alone.