Inheritance of dyslexia
Will my child inherit dyslexia from me?
Although dyslexia tends to run in families, there is no way to know whether an individual child will develop symptoms of dyslexia. Although there is a genetic influence, dyslexia is similar to any other mental aptitude or ability (or weakness). A child may or may not inherit the tendency to develop dyslexia from her parents. Even if the child does inherit the genetic tendency, the child may not actually experience problems usually associated with dyslexia.
Researchers who have studied identical twins have found that where one twin is dyslexic, the other will have dyslexia about 55 to 70 percent of the time, depending on the type of dyslexia. This research shows that there is a strong genetic influence, but that environment and life experiences also play a role in the development of symptoms.
Dyslexia probably is not caused by a single gene, but by a combination of genetic traits. The traits also may be expressed differently among different people, because of mediating or enhancing influence other genes.
Because of that it is unlikely that there will ever be a genetic test to diagnose dyslexia. At best a person’s DNA profile may help to determine whether they have a higher risk of developing dyslexia.
Of course, if there is a family history of dyslexia, that is valuable information to keep in mind when making educational decisions, especially if the child seems to be experiencing difficulty or frustration during early school years.
(Answer by Abigail Marshall)