At 22 weeks, Roxanne Robertson had a scan which revealed her baby had joined fingers on each hand and claw-like feet.

“That’s all they could tell me,” she said. They offered me an abortion right up until I was seven months but I’d already felt my baby move and kick, heard its heart beat and seen its face so it wasn’t an option for me.

“I didn’t know what to expect and people kept giving me hope she would be able to do everything like other children so I kept thinking ‘what’s a few joined fingers?’ I kept thinking ‘it’s going to be fine’.”

The then 18-year-old spent the rest of her pregnancy travelling to King’s College Hospital in London every Tuesday for an ultrasound.

At 38 weeks, Lilly-Ann was born via a planned C-section at 2.50pm on September 21, 2007, at Medway Maritime Hospital, Gillingham.

She was taken to the Oliver Fisher Neonatal Unit where she stayed for 12 days.

To the outside world she looked normal except for the fact she had seven fingers on her left hand, six on her right and her feet were curled under.

Like all new mothers, the teenager watched her daughter for her first milestones. At five weeks she smiled and at three months she was trying to roll over but then progress stopped.

Speaking about how she is at the moment, the 25-year-old said: “She can’t talk, walk, sit unaided, clean or feed herself.

“She is in nappies and completely adult dependent. The doctors did some tests before she turned one but they couldn’t find anything.”

Over the years she underwent three operations to remove the extra digits from her hands plus two for anal reconstruction and to fit and remove a colostomy bag.

After almost dying from bronchitis, she underwent further surgery aged three to fit a gastrostomy which allows a special feeding formula to pass straight into her stomach.

Then, when Lilly-Ann was five, she was invited to join the Deciphering Developmental Disorders study at The Welcome Trust Sanger Institute.

Little did the mum-of-three know it would give her much-needed answers, or reveal how unique the Meadowfield School pupil’s condition could be.

“They did the tests and a year-and-a-half later I got a phone call from Guy’s hospital saying she’s got a defect in the MED12 gene,” said the former Minster College pupil. “They say she is the first girl ever to be reported with it in the world.

“It only happens to boys because girls have two X chromosomes, so if there’s one faulty X chromosome the other one takes over. Boys only have one so it can’t shut down because it doesn’t have another to fall back on.

“They took a skin biopsy on September 16 because they need to find out more. It will be a lengthy process [until we find out more].

“The biggest thing for me has been not knowing what the condition is and her life expectancy.

“It turns out it’s normal so I was like ‘phew, what a relief’. I would love to take some things away from her like the surgery and when she’s poorly because those are things no child should have to go through but I wouldn’t change her, she is as she is.

“Lilly-Ann’s happy and as healthy as she can be and for that we’ve got to be grateful.”

While she can’t communicate verbally, she does understand things.

She added: “I know when she is in pain through her cry but it’s hard to figure out where she’s in pain.

“She smacks her lips together when she’s thirsty. She moans when she’s bored. If I put the wrong film on she shouts until she gets the right one.

“We often hold up a selection of toys or films and she tries to guide me to what she wants. She looks away if she’s not interested.

“At school they’re doing eye-gazing on a commination board. She knows body parts, animals, shapes and colours. Next they’re going to try her on an eye gaze computer. It could provide me with another way of communicating with her.”

The family home in Sheerness has been altered to accommodate a downstairs bedroom and wet room so Miss Robertson can care for the seven-year-old.

In addition she has two sons William, three, and Tommy, two, to look after – so how does she cope?

“My friends and family have been brilliant,” she said. “They’ve supported me from the word go. I wouldn’t have coped without my mum Kim. I lived with her in the early days.

“William likes to help me when I’m giving Lilly her medicine or he tells me when she wants something.

“I get worried about when the boys are older if they’ll be bullied because of their sister.

“We went on a two-week holiday to Spain recently with them and Lilly-Ann stayed with my mum. I want to give them as normal life as possible because I feel that if we stop the boys from doing things they will end up resenting me and Lilly when they’re older.”

If anything she says it’s people’s reactions to her child which have been the hardest thing to deal with.

“I don’t like people staring,” she said. “I can handle children because they don’t know any better. When adults do it I give them the middle finger because I think it’s rude. I would rather someone asks me than stare at her.

“If there’s one thing I’m hoping for it’s that this article will stop people from staring at her – even if it’s just one or two.”

Dr Charu Deshpande, consultant in clinical genetics at Guy’s and St Thomas’ NHS Foundation Trust, said: “When Lilly-Ann was little, in addition to the limb problems that were immediately obvious, she was floppy and she needed help with feeding.

“We thought there must be a genetic reason for her problems. At six months she had only grown to the size of a two-month-old.

“It was a challenge to pinpoint what the genetic reason was, but we were able to enrol Lilly-

Ann onto a DNA sequencing study with other children with similar complex problems like hers.

“Further tests are planned, and it will be many months before we have definitive results, but we are now in the process of trying to work out if we have at last got the correct answer for her.”