Doctors have told a woman whose legs won’t stop growing that they have developed a promising treatment for her after mapping her DNA.

Mandy Sellars, 38, has a condition that has caused her legs to grow uncontrollably her whole life.

She even had her massive left leg amputated after it became infected with septicaemia. But the stump soon started growing again and within three years measured a metre in circumference and weighed 3stone.

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Mandy discovered she couldn’t be fitted with special prosthetics as her legs had grown too big

Ms Sellars has now been told it has no name after genetic testing revealed it was the first case of its kind in the world.

The condition makes it incredibly difficult for Mandy to move around and she is housebound during the week. She travels in a specially reinforced wheelchair.

Doctors had hoped to fit her with a prosthetic leg but as her stump kept growing, new legs had to be made and to date she is still unable to walk.

Mandy Sellars, pictured on This Morning in her electric wheelchair, said she has a ‘zest for life’

‘I find it incredibly frustrating,’ Ms Sellars, from Huncoat in Lancashire, said.

‘I have such a zest for life and I really want to get out there and live it.’

This could now be a possibility, after scientists at Cambridge University took an interest in Ms Sellars’ case.

Over the past year, Dr Robert Semple has mapped her DNA from blood and tissue samples. Ms Sellars’ presumed she had a rare form of Proteus Syndrome – the condition that affected the Elephant Man. However, the analysis revealed she had a unique disorder.

‘I’m the first person in the world with it and it hasn’t even got a name yet,’ Ms Sellars told ITV’s This Morning.

‘I keep suggesting Dr Semple call it Sellars Syndrome!’

As a result, Dr Semple’s team have come up with a medication aimed at replacing her unique mutated gene with a therapeutic gene.

‘I started taking it in September and the aim was to stop my limbs growing further. Actually they have started to shrink a little,’ Ms Sellars’ said.

‘I just kind of accepted my condition would get worse and keep growing but I am more optimistic following the discovery.’

Ms Sellars, who is a size 12 on her top half, has had to deal with her one in seven billion condition her whole life.

Ms Sellars with the medication she hope may reverse her condition

Dr Robert Semple mapped her DNA and found out her condition was unique and she was the only person in the world with it

‘There was clearly something dramatically different about me when I was born as my legs were so much bigger than my body. Doctors didn’t know what it was and whisked me away – they didn’t let my mother see me for two weeks. They didn’t think I would survive.’

Her left leg was three inches longer than her right, and both were out of proportion. But Mandy flourished despite their dire prognosis.

VIDEO I was an active child. Mandy reminisces about time legs were smaller

‘I could walk around and play football as a child,’ she said.

‘I had friends and went to a comprehensive school for my GCSE’s. But I found it harder to deal with as a teenager as you become more aware. Some people would stare and laugh at me. I find that easier to deal with now.’

Her parents encouraged her to be independent and she moved out of home at 19. She went to the University of Central Lancashire where she gained a BSc in Psychology.

She has volunteered in the past at the RSPCA but had not been able to work full-time due to her health condition. She has suffered arthritis, deep vein thrombosis (DVT) and had a blood clot in her leg.

Mandy assumed she would end up bed-bound after her leg stump started growing again after the limb was amputated

Mandy is determined to maintain as much independence as possible

Ms Sellars had a spinal stroke in 2002 that paralysed her for two months, and all the while her legs kept growing. In 2005 she got a blood infection, then her kidneys failed and she got MRSA.

By 2008 her left leg was five inches longer than her right with a club foot that turned backwards and together they weighed 15stone.

She had her left leg amputated above the knee in 2010 after developing blood poisoning. But the stump began growing rapidly again.

Despite all the hardships she has faced, Ms Sellars remains optimistic.

‘I really miss travelling and I hope one day to walk again,’ she said.

‘I’m stubborn enough to make it happen!’