Louise Berman has no feeling below her left knee but that will not stop her trekking almost 27 miles through the capital this weekend.

Ham & High: James BerwinJames Berwin (Image: Archant)

The 60-year-old, of Lyttelton Road, Hampstead Garden Suburb, will walk the London Marathon on Sunday with the assistance of her trusty four-wheeled walker to raise money for a cancer charity.

In September, Ms Berman’s 28-year-old son James, a trainee orthopaedic surgeon, was diagnosed with Hodgkin lymphoma and is now relying on a stem cell transplant to save his life.

Ms Berman, who has been registered disabled since severing a nerve in her leg during a freak fall eight years ago, is determined to cross the finish line on Sunday to raise thousands of pounds for charity Leukaemia & Lymphoma Research.

Recalling her reaction to James’s diagnosis, she said: “He phoned me at work and said, ‘Can I have lunch with you?’ He told me and it was just hideous because what do you do? You can’t kiss it better.

“The worse thing of all is that you relinquish control because it’s the cancer that is in control, not you. So you can’t plan to do anything. He had his entire career mapped out and it’s all being put on hold.”

On Sunday, Ms Berman, who works for an equity management firm in the City, will be joined on the walk by her friend Elizabeth Shrager, of Wedderburn Road, Hampstead.

Six years ago, Ms Shrager’s husband Robert died of myeloma, another blood cancer. Both women are passionate about the work of Leukaemia & Lymphoma Research.

“I started to read about the research they were doing,” said Ms Berman. “It turns out they need £20million a year and I thought, ‘I need to do something. I have to do something positive, I can’t sit here and let this happen.’

“If you can’t be positive then you’re going to go under so I just have to keep being positive and pushing myself forward.”

Simon Murrell, of Mansfield Road, Gospel Oak, is also taking part in Sunday’s marathon.

The musician is running in support of charity Beating Bowel Cancer in memory of his mum Christine, who died from cancer in 2012.

He said: “Seeing how cancer affected mum and her amazing courage facing it had a profound effect on us all.

“As Mum was so appreciative of others, was such a giving person and so supportive of charitable causes, I knew she would want me to do all I could to express our thanks, to give something back, to help others.”

If you wish to support Ms Berman and Ms Shrager’s fundraising efforts, visit justgiving.com/louise-berwin. To support Mr Murrell, go to justgiving.com/Simon-Murrell1