'Gene therapy is a game changer for our son'

'Gene therapy is a game changer for our son' Baby Arthur is just five months old. He has no way of knowing the treatment he is receiving in his right arm is the world's most costly medicine.

His devastating progressive disorder causes loss of muscle control.

But he has become one of the first patients to be treated on the NHS with Zolgensma, a gene therapy with a list price of £1.795m. BBC News