Average age of diagnosis
In most countries, the average age of diagnosis of DMD is above 4 years of age and the diagnostic delay around 2.5 years. Parents see symptoms much earlier and some symptoms are already visible when the children are very young. Lack of awareness of DMD in (first line) health care professionals seeing these children is a major factor that contributes to this delay.
With the current standards of care, people with Duchenne can live into their early 30s and beyond. However, still a certain percentage of boys with DMD die in their late teens, mainly due to cardiac complications. The average life expectancy of Becker patients is somewhere between 40 and 50 years. However, with clinical care continuing to improve, as well as clinical trials, research and new therapies, the quality and quantity of life with Duchenne and Becker are enhanced each year.
Depending on a lot of factors including the type of mutation, Duchenne and Becker are different for every person. Even a sibling, having the same mutation, can have a different progression. The different stages in which Duchenne and Becker people are divided are based on whether patients are able to walk (ambulant) or not (early loss of ambulation, late loss of ambulation).