If my child has DMD, does that mean that other family members have the DMD gene?

Not necessarily. In about half of DMD cases, the fault in the child's gene has not come from the parent. Instead, the fault has arisen while the child's cells were being formed. This can happen if a 'mistake' is made when the parents' genes are copied into the cells which will make the child.

About half the children with DMD will not have family members carrying the gene. DNA testing and specialised genetic advice can help you find out whether the Duchenne gene is carried by other members of the family.