Developmental Delay & Intellectual Ability (IQ)

Children with Duchenne are at increased risk for developmental delays. The most common delays are in gross motor skills such as sitting, walking, and running. However, people with Duchenne are also at increased risk for delays in other areas such speech/language development, motor planning, and fine motor dexterity. Some children are later than usual in potty training and self-help skills.

Similar to the general population, IQ scores in Duchenne can range from well above average to below average. Most people with Duchenne have an IQ that is in the normal range. However, they are also at increased risk for having an IQ that is below average or in the mental retardation range (IQ score less than 70). People with Duchenne may also have a specific pattern of cognitive strengths and weaknesses that may not be accurately represented in an overall IQ score. Thus, educators and parents should take care when interpreting IQ scores for Duchenne children.


  • Interventions for developmental delays (e.g., speech/language, physical therapy, and occupational therapy) should be targeted on improving specific skills.
  • Interventions typically involve various therapies focused on improving specific skills.
  • Children with intellectual impairment will need significantly more repetition, rehearsal, and practice to learn new academic information.

Information in this section was contributed, in part, by James Poysky, PhD. Read Dr. Poysky’s entire document, Learning and Behavior in Duchenne (download).