To ask the Secretary of State for Health how many children were diagnosed with spinal muscular atrophy types (a) 1, (b) 2 and (c) 3 in each year since 2005. (175291)

We do not collect that information centrally. However, NHS Direct estimates that one child in 25,000 will develop one of the three forms of spinal muscular atrophy and that one in 300,000 people will develop type four as an adult.