Our daughter came back ill after first holiday with mates…doctors thought was tonsillitis but weeks later she was dead

The life-threatening immune condition is caused by a build up of white blood cells in organs when someone's immune system doesn't work normally.

It eventually causes organ failure as it destroys healthy cells and can be caused by certain conditions or diseases including infections.

Doctors had initially issued Leah with antibiotics in order to make her more comfortable with her suspected tonsillitis.

After several trips to hospital she was later diagnosed with glandular fever but her condition worsened and the worried family were advised she had been suffering from liver failure.

Leah, from Neath, Wales, was then transferred to the Queen Elizabeth Hospital in Birmingham and diagnosed with the rare condition.

The 17-year-old was transferred to the intensive care unit and ventilated as her condition gradually deteriorated.

Her family were able to say their final goodbyes after being informed she would likely not make it through the night before she tragically passed away.

Leah's brave family have now began their efforts to help raise awareness of the devastating condition with hopes of preventing future sufferers and families from the "excruciating pain we have endured". 

Heartbroken father Hugh said: "It all happened so suddenly and our lives will never be the same. She has left a massive void in our hearts – one that can never be replaced"

"She was a very intelligent person and intended to become an intensive care nurse or accident and emergency nurse after she left school.

"She was a bright people person and passionate about life. She had a fantastic sense of humour and was constantly impersonating people and was called 'the mum' by her group of friends – she was very dependable and caring.

"She was the perfect 17-year-old daughter – smart, funny, charismatic, and bubbly."

Hugh said the situation is "incredibly difficult" as they all have moments of struggle but they continue in her spirit.

"We all just can't comprehend it – we all think this is just a bad dream that one day we can wake up from and she will be there," Hugh added.

The idea for fundraising to spread awareness came from Leah's siblings – sister Becky, who is 31, and brother Ben, 24.

The siblings have made plans for future charity events in her honour in September to mark what should have been Leah's 18th birthday.

Support for the fundraiser and the family have come from all directions including friends and local businesses and even a vlogger who learned of the tragedy.

Leah's family have said that the love and support during this difficult time has helped them find comfort.

Hugh added: "We just wanted to say thank you to everyone who has helped us so far. Their words and support have meant so much during this difficult time.

"Baglan Funeral Home have been supporting us through every step of the way and Dinner Jackets and Deli in Port Talbot donated the money we spent as a donation – I can't thank both of them enough.

"Both Birmingham and Bridgend hospital did everything they could to help our Leah and unfortunately it wasn't to be but we can't thank them enough. We hope to prevent others going through similar."