On the 12th April I'll be running 42.2km in the 2026 Brighton Marathon to raise funds to save Leni.

Last year, my childhood friend Emily and her husband Gus were faced with a heartbreaking diagnosis for their two-year-old daughter Leni - an extremely rare and very severe rapidly neurodegenerative genetic condition called Sanfilippo Syndrome Type B (MPSIIIB), also known as Childhood Dementia.

Time is against us, and we need your help to save Leni.

Life-saving treatment may be available to her this year, but we need to urgently raise funds for her to access this. With Leni’s condition every day matters and time is running out to save her life.

Children with this condition have a defect in a single gene that prevents them from breaking down a sugar molecule called heparan sulfate, causing toxic waste to build up in the brain and body.

Sanfilippo Syndrome is unimaginably cruel. Children develop relatively ‘normally’ with no obvious symptoms until they are around two years old, then over a short amount of time they lose all skills once learned, experience severe behavioural challenges, extreme hyperactivity, insomnia that can last for days, seizures, a total loss of cognitive and motor function, and a premature death in their early to mid teens, as well as many other horrific symptoms. Sanfilippo is relentless and leaves nothing untouched.

Leni will lose the ability to walk, talk, play, laugh, eat, and eventually her life to this condition.

Like most of the world, Emily and Gus had never heard of Sanfilippo Syndrome until very recently, and it is now part of their every waking moment and has ripped their world apart. No parent should have to go through this heartbreak, and no child should have to suffer with this syndrome.

There is currently no treatment and no cure, but there are promising experimental treatments on the very near horizon that have already been proven to be incredibly effective. Everyone is working very hard to make this treatment urgently accessible to those who need it, and Leni's parents will do whatever they can to get Leni and other children access to the treatment that they desperately need, but at the moment it is just out of reach.

Time is working against Leni. With Leni’s condition weeks and months matter as toxic waste builds up in her tiny body every single day and the damage cannot be reversed once it is done.

The difference between her getting access to this treatment now and in a year's time could be the difference between a potentially near-normal life and a significantly shortened life with the most severe mental and physical disabilities you can imagine. It’s now or never for Leni.

It is every parent’s worst nightmare to be told that their child is going to die, and that is the haunting reality that Leni's parents are faced with if she cannot get access to treatment and fast. This truly is her only hope.

Please donate if you can, or if you can't please share, and help us to save Leni.

Follow: Saving Leni

All donations will be added to Leni’s primary gofundme campaign here

More information here about Sanfilippo Syndrome