SUBJECT: Duchenne Muscular Dystropy
MESSAGE: My stepson had DMD and passed away at the age of 20.  My step daughters are both carriers.  The oldest one had a healthy son, the youngest daughter had a son with DMD this month at the age of 17.  My question is about my other step son's daughters.  Is it possible our grand daughters are carriers and do they need to be tested.  We are worried about this.

Summarized question: What is the inheritance pattern for Duchenne Muscular Dystropy?