Child in a million. Part 1, Molly and Tahlia.

The first in a six-part series following the stories of children undergoing pioneering treatments for rare medical conditions at London's Great Ormond Street Hospital. This part tells the moving stories of Molly and Tahlia. Molly is a four-year-old girl who developed a Wilms' tumour which then, very unusually, spread to her lungs. One-year-old Tahlia was rushed to the hospital unable to breathe due to an extremely rare condition called long segment tracheal stenosis which only happens to one in five million children. The programme involves scenes from the operating theatre at Great Ormond Street.