It is estimated that one in 40 (forty) people in the United Kingdom is a carrier of genetic mutation that causes SMA. When two carriers have a child, there is 25% risk that the child will have SMA. Considering varying life expectancy among SMA types, it is speculated that between 500 and 2,000 people in the UK live with SMA, including children, teenagers and adults with all SMA types.
In an epidemilogical review of SMA commissioned by SMA Support UK, an attempt was made to calculate the total population living with SMA in England. The results of the study suggested that 85 children were born with SMA in England in 2012.
For more information see SMA Support UK: Population Statistic Breakdown.