A US lawmaker has been diagnosed with a rare and incurable neurological disorder, forcing her to bow out from seeking re-election in 2024.
Democrat House Representative Jennifer Wexton has been diagnosed with progressive supranuclear palsy, a condition she described as "Parkinson's on steroids".
She was elected to represent Virginia's 10th congressional district in 2018.
Ms Wexton said she was "heartbroken" to give up public service.
"This new diagnosis is a tough one," Ms Wexton said in a statement. "There is no 'getting better' with PSP."
The 55-year-old lawmaker, who was diagnosed with Parkinson's disease in April, had said at the time that she would seek treatment and continue to serve in office.
"I'm doing well, and I want to bring about as much good from this diagnosis as I can—including here in Congress," she said on social media at the time.
But in her most recent statement, Ms Wexton said her symptoms had not improved in the way that she had hoped, which led her to discover that she had a rare form of Atypical Parkinsonism.
"I sought out additional medical opinions and testing, and my doctors modified my diagnosis to Progressive Supra-nuclear Palsy - a kind of 'Parkinson's on steroids'," she said.
Progressive supranuclear palsy - or PSP - is caused by the deterioration of cells in areas of the brain that control movement, thinking and other important functions, according to the US National Institutes of Health.
There is no cure for the rare disease, and it is often misdiagnosed as Parkinson's disease in its early stages, as symptoms can be similar. But it is known to progress more rapidly than Parkinson's.
Given the diagnosis, Ms Wexton said she would continue to serve the duration of her term but will step back from public office in 2024 to spend "valued time" with family.
"I'm heartbroken to have to give up something I have loved after so many years of serving my community," Ms Wexton said.
"But taking into consideration the prognosis for my health over the coming years, I have made the decision not to seek re-election once my term is complete."
The lawmaker had previously been a prosecutor, attorney and a state Senator in Virginia before she was elected to Congress in 2018. Experts say her decision not to seek re-election in 2024 could make Democrats vulnerable in a seat she won after defeating a two-term Republican incumbent, Barbara Comstock, by 12 percentage points.