Can you tell me if there are any mental or physical disorders that would prevent a child from writing?

See Your Doctor. Your child's age is unknown. Writing difficulty points to learning disability (LD) written expression. Other forms based upon disability are reading & math. Up to 20% of children have a form of LD. Failure to recognize LD leads to low self-esteem, behavior probs, school failure, depression, & more. Early diagnosis is key. See your doctor for correct diagnosis & treatment. .