The condition the three children were suffering from meant they were unable to talk or walk and were slowly dying.
It has been described as an incredibly debilitating disorder.
The four-year-old girl was diagnosed first followed by the younger twin boys.
More top news
One of the country's most extravagant private homes has been snapped up for just a quarter of the original £100 million asking price
Transport for London is being forced to pull down Germanwings tube adverts with the words "get ready to be surprised" after the fatal crash
Two huge boring machines are entering the final stage of their 26 mile journey underneath London's streets