A WOMAN who spent years suffering from a life-threatening hereditary disorder has described how a clinical trial changed her life.

Sian Harding, from Benfleet, who was born with hereditary angioedema, participated in a trial at Addenbrooke's Hospital in Cambridge.

Patients with this disorder have a defect in the gene which controls a blood protein, leading to episodes of swelling in various parts of the body, including the hands, feet, face, and airway.

This can result in death by asphyxiation.

Now 33 years old, as a child, Sian was a frequent emergency case at Basildon Hospital due to abdominal pain and vomiting.

Her treatment involved twice-weekly injections to control symptoms, a process fraught with complications including infections, more pain, and time off school.

At 17, she became the first person with hereditary angioedema to be taught to inject herself as the unpredictable swellings moved from her stomach to various parts of her body, sometimes making walking impossible.

Now, thanks to the international clinical trial, Sian has gone from injecting herself twice a week to manage the excruciating symptoms to living a normal, happy life.

She said: "Taking part in this trial is the best thing I have ever done.

"It has 100 per cent altered my life – it’s a total game changer.

"I feel like a new person with a different, happier personality.

"This year we had a three-week road trip to Spain, which was simply bliss.

"For the first time I wasn’t going to bed having to worry about waking with an attack.

"For the first time I’m able to dare consider what it might be like to have children and be well enough to look after them."

Sian was referred to Addenbrooke's Hospital and offered a place in the second phase of an international clinical trial last November.

Along with 27 other patients worldwide, she underwent a single infusion of an investigational therapy, which targets the gene responsible for producing plasma prekallikrein.

This therapy reduces the levels of total plasma kallikrein, effectively preventing swelling attacks.

The results have been so successful that they have been published in the New England Journal of Medicine.