A large study published in the Journal of Speech, Language, and Hearing Research systematically analyzes the genes that have so far been proposed to be involved in specific reading disability (SRD) — commonly called dyslexia, a term the authors consider inappropriate.

Questions about the genetic origins of SRD first arose in 1983. Since then, scientists have wondered whether reading problems stem from specific genes that emerged during human evolution or from a much older genetic basis.

The study suggests SRD originates from subtle alterations in very ancient genetic networks that predate modern humans and are shared by many vertebrates. Those networks are central to brain development and synaptic transmission, which helps explain why SRD often coexists with other neurodevelopmental disorders.