Parents Emily, 33, and Angus, 35, from London, have shared the agonizing decision to terminate their much-wanted second pregnancy after discovering their unborn child also carried Sanfilippo syndrome, a rare genetic disorder dubbed 'childhood dementia.' This heartbreaking choice came after their two-year-old daughter, Leni Forrester, was diagnosed with the same devastating condition.

Leni was born seemingly healthy, but the family's lives irrevocably changed six months ago when a close family member's genetic testing revealed they carried a recessive gene for Sanfilippo syndrome. This degenerative disease causes children to gradually lose all learned motor skills, such as walking, talking, and eating, by their teenage years. There is currently no cure, and most diagnosed children tragically die by their mid-teens.

Upon learning about the gene, Angus underwent testing, especially after noticing Leni exhibited classic symptoms including speech delay, hearing difficulties, and unusually bushy eyebrows. Initially, his test came back negative, and the couple began trying for a second child. However, weeks later, they received the devastating news that Angus's test results were incorrect; he was indeed a carrier. Heartbreakingly, Leni was then diagnosed with Sanfilippo syndrome in October 2025.

Just two weeks after Leni's diagnosis, the couple discovered they were pregnant again. Ms Forrester described this period as navigating 'the heartbreak of Leni's diagnosis and our new world as parents to a child with very complex medical needs.' She had to carry the foetus for three months before in utero genetic tests could be performed. Despite a 75 percent chance the baby would be unaffected, they tried to detach emotionally from the pregnancy, yet 'couldn't help but cling on to that hope' of growing their family.

Sadly, in utero testing confirmed that their growing baby would also be born with Sanfilippo syndrome. Faced with this knowledge, and with no treatment options, no cure, a catastrophic prognosis, and poor quality of life, Emily and Angus felt they had no choice but to terminate the pregnancy to focus all their efforts on Leni. Ms Forrester reflected, 'It was the most heartbreaking and difficult decision we have ever had to make. But we knew deep down there was no choice.' The surgical termination occurred a few days before Christmas.

Sanfilippo syndrome is inherited when both parents carry one copy of a defective gene, which prevents the body from breaking down heparan sulfate, a type of cellular waste. This toxic waste accumulates in the brain and other organs, destroying cells. Beyond speech and developmental delays, early symptoms can include prominent, thick eyebrows, coarse hair, full lips and nose, fast breathing after birth, a larger head size, excessive body hair, and sleep disturbances.

Despite the severity of her condition, Leni is described by her parents as 'a bundle of energy' and 'pure sunshine.' However, they are in a race against time, knowing that 'weeks and months matter as toxic waste builds up in her tiny body every single day and the damage cannot be reversed once its done.' The difference between early access to treatment and a delay could mean a 'potentially near-normal life' versus a 'significantly shortened life with the most severe mental and physical disabilities.'

While there is currently no known cure for this neurodegenerative disease, which affects an estimated one in 200,000 births, a clinical trial for a potential gene therapy treatment is expected to begin in the US later this year. This treatment aims to deliver a missing gene into the patient's bloodstream via stem cells. Leni's parents are urgently calling on the UK Government to help fund this research to include children like Leni in the trial. They have already raised over £360,000 for this cause and are advocating for newborn screening to detect rare genetic conditions earlier and for more funding to accelerate treatments, highlighting that when grouped, 'rare' diseases have a much broader impact than many realize.

Alongside their fundraising efforts, Emily and Angus are determined to 'make the most' of the time they have with Leni, planning to 'travel, go on adventures and make memories as a family that we can treasure for life,' all while fighting for her only hope for treatment.