A SEVERELY disabled Northumberland boy whose "unique" condition made experts think he would not survive birth has died aged 13.

Adam Williamson, from Alnwick, suffered from extremely rare VACTERL Association, which is an assortment of birth defects.

VACTERL is an acronym of various conditions and most sufferers possess three of them.

However, Adam is said to have suffered from all of them and “a little bit more”, leading health experts to describe him as “unique”.

Some believed he would not survive birth, while one said he would struggle to make it past his second birthday.

Adam’s condition left him reliant on tubes for feeding, and he also required 24-hour oxygen.

He was unable to talk, had learning difficulties and was unable to walk until he was aged 11.

Adam only had one kidney, holes in his trachea and oesophagus at birth, and had cardiac defects.

He had surgery on the day he was born and endured many complex operations in his life.

At the age of two and a half, he had his tonsils and adenoids removed, and this stabilised him substantially.

However, he still remained a very sick child.

But last night, following his death, Adam’s mother Heather Williamson told how she felt “proud” that he had chosen her as his mum, and paid a loving tribute to her happy son.

Mrs Williamson, 49, and husband Scott, a 48-year-old dentist at Alnwick’s Market Street Dental Practice, first found out something was wrong with their son during pregnancy when it was discovered he had only one kidney, holes in his windpipe and oesophagus, and a heart defect.

Adam was delivered by cesarean section at Newcastle’s Royal Victoria Infirmary six weeks ahead of his due date.

He was in intensive care for the first 10 months of his life, and in and out of it until he was two and a half.

By then, the youngster had had four or five cardiac arrests and had to have his tonsils and adenoids removed.

His condition left him having to breathe and eat through tubes.