THE brother of a woman battling one of the world's rarest diseases is taking to the saddle to raise money for vital medical research into the condition.

James Blackburn from Silverton is gearing up for a sponsored 100-mile cycle to support his sister Helen who was diagnosed with the disease in 2008.

He is fund raising for LAM Action, which supports patients with lymphangioleiomyomatosis (known as LAM), an incurable lung condition that affects only women.

The 47-year-old is taking part in this year's Prudential RideLondon-Surrey 100 on August 10 starting at the Queen Elizabeth Olympic Park in London.

Father of two James, said: “I love my sister and want to help her in any way I can.

“LAM Action is a small charity that's doing an amazing job, but it needs every penny it can get to fund research into an effective treatment.”

Helen Sabin from Leamington, who has two young children, was diagnosed with LAM after suffering a collapsed lung six years ago.

She is one of only around 150 women in the UK with the progressive condition which causes cysts to develop in the lungs and can make it difficult to breathe.

Helen said: “I found the whole diagnosis very traumatic, it was horrendous because I had two young children and my mother was also very poorly.

“It was an extremely difficult time, but I had so much support from LAM Action that it helped me through a very difficult period.”

Helen has been able to control the progression of LAM by taking the medication Rapamycin and uses an oxygen canister to help her breathe.

But, she is unable to walk any great distance, can no longer run, or play her favourite sport, netball.

James took up cycling last year three weeks before completing his first sponsored 100 mile ride for Helen.

And now, as befits his green credentials, he cycles nine miles to work each day and back to his office in Market Street, Exeter.

He is one of 80,000 riders to take part in the traffic-free Prudential RideLondon-Surrey 100 cycle race.

The 100-mile route goes through the capital into Surrey towards Dorking to the world-famous zig-zags of Box Hill, and returns to The Mall in central London.