The parents of a little girl diagnosed with ‘childhood dementia’ have shared their heart-wrenching decision to end their second pregnancy after learning that their unborn child had the same rare condition.
Leni Forrester, two years old now, seemed perfectly healthy at birth to her parents, Emily, 33, and Angus, 35, who live in London.
However, their lives took a turn six months ago when a close relative discovered they carried a recessive gene linked to Sanfilippo syndrome, a severe genetic disorder often referred to as childhood dementia.
This degenerative illness leads children to steadily lose motor skills—like walking, talking, and eating—as they approach their teenage years. Currently, there are no treatments available, and most affected children do not survive past their mid-teens.
The likelihood of both parents carrying the gene is low, but when they noticed Leni showing some classic signs—like speech delays and hearing issues—Angus underwent genetic testing as well.
Fortunately, his results were negative, and they began trying for a second child.
But just a few weeks later, the couple was devastated to discover that the initial tests had been incorrect, leading to what they described as overwhelming grief.
In October 2025, Leni was diagnosed with Sanfilippo syndrome, and shortly after that, the couple found out they were expecting again.
Emily mentioned, “We knew this pregnancy would either bring us immense joy or unimaginable sorrow.”
Dealing with Leni’s diagnosis, as well as the everyday challenges of raising a toddler, made the situation even more complex. She eventually could only have the fetus tested after three months due to timing issues, which would determine if the new baby would have the same condition.
Though they tried to stay detached from the pregnancy, a 75 percent chance that their unborn child might be unaffected gave them some hope, even if they also felt nervous.
They longed for more children so Leni could share her life with siblings.
Sadly, testing revealed that their new baby would also have Sanfilippo syndrome.
Faced with this devastating knowledge, they felt they had no choice but to terminate the pregnancy and devote their energy to Leni instead.
Emily stated, “Without any treatment options or a cure and a grim outlook on life quality, how could we knowingly bring another child into a world with this condition?”
She added that the decision wasn’t taken lightly: “It was the most heartbreaking and difficult choice we’ve ever had to make. But deep down, we felt it was necessary.”
She emphasized, “Unless you’ve faced such a heart-wrenching diagnosis, you can’t fathom the pain we endured.”
While there’s no known cure for the neurodegenerative disorder affecting about one in 200,000 births, a clinical trial for a potential treatment is set to start in the U.S. later this year.
The couple is now urging the UK Government to support research that would enable trials to include children like Leni.
Emily remarked, “With Leni’s condition, every week and month matters as toxic substances accumulate in her tiny body and irreparable damage occurs.”
Despite everything, Leni’s parents describe her as a lively and joyful child who brings happiness to those around her.
Yet, as they celebrate milestones, they remain acutely aware that time is not on their side for treatment options.
Emily shared her fear of watching their daughter lose basic abilities due to the progression of this condition.
She believes that securing treatment sooner rather than later could dramatically affect Leni’s quality of life.
They’ve raised over £360,000 to secure access to potentially crucial treatments for Leni and children like her.
The treatment aims to supply a missing gene via stem cells, but significant funding is needed to initiate clinical trials.
Additionally, they are advocating for newborn screenings to detect rare genetic disorders early and for increased funding for expedited treatments.
Even though conditions like Sanfilippo syndrome are rare, Angus pointed out that when considered collectively, these rare diseases have a larger impact than many might think.
“When you combine all these rare conditions, they don’t seem so rare anymore,” he noted.
