'Mummy, is Arlo going to die?' His sister's heartbreaking words, just hours before Arlo Upton passes away following a 48-hour sickness

Arlo Upton’s three-year-old sister asked his mum if her little brother was going to die just hours before he passed away.

The two-year-old from Brisbane’s death on November 1 shocked the country because his only symptoms were a cough and temperature and doctors assumed her had contracted a virus.

His sister, Frankie, visited her brother in hospital and realised he was very unwell.

“Frankie asked why his tongue was protruding from his mouth and said in the car on the way home ‘Mummy, is Arlo going to die?’, his mum Kate Upton told 9News.

“She’s been amazing. She’s been drawing pictures. I don’t know what I’d do without her.”

It took just 48 hours for Arlo to have several symptoms and to then pass away.

Kate and Ross Upton, the parents of the toddler, initially were told by doctors their son had contracted a virus.

Inexplicably, Arlo suffered a seizure and died 48 hours later.      

The toddler first displayed signs of illness when he started coughing on October 27, just before the family headed out celebrate Halloween. 

After a visit to the doctor, his temperature did reduce but little Arlo developed a worrying rash. 

He was refusing to eat and his body temperature hit almost 40C, and wouldn't go down. 

The parents visted doctors three times only to be told he had a virus, but when he started to turn blue around his mouth, his parents called an ambulance.

His condition deteriorated rapidly and he was placed on life support after going into cardiac arrest.

'It went from OK to bad, really quick,' Mrs Upton, 34, told 9 News.

Medics initially felt Arlo could be suffering from sepsis, however when they brought him into hospital they re-diagnosed him as having a gene mutation called LPIN1 deficiency. Worringly, the family will now need to be tested to see if Frankie could have it too. 

At one point his parents were told Arlo might have to have his fingers or toes amputated to save him, but it was too late. 

Arlo’s funeral will be held today and guests will be served Mexican food and M&M’s. A garbage truck will also be there – one of his favourite things.