Genetic research has shown that dyslexia is familial, substantially heritable, and heterogeneous in its genetic mechanisms. Evidence also supports the view that the primary symptom in dyslexia is a deficit in the phonological coding of written language, a symptom that appears to be heritable. (Author/JDD)

This study of 11 3-generation families supported the hypothesis of autosomal dominant inheritance with reduced penetrance. Data did not support an increased frequency of males, left-handedness, or autoimmune disorders in dyslexics. Severity was greater in males. Long-term outcome was comparable in dyslexics and nondyslexics. (JDD)

Church records of adult reading abilities as evaluated yearly by Swedish priests were examined from the eighteenth century in families characterized by poor reading and good reading ability. Although descendents of poor readers tended to demonstrate lower reading scores, transmission patterns did not indicate a simple genetic mechanism. (Author/DB)

Pedigree analysis of 12 young adults (9 of whom had learning disabilities) indicated that learning disability (LD) was strongly familial but that the type of disability (reading or math) was not directly inherited. Autoimmune disorders were significantly correlated with LD. In seven of the LD families, adults failed to overcome earlier reading and…

Described are the history of the study of language disabilities, briefly outlining the work of Samuel Orton, Judson Herrick, Adolph Meyer, and Paul Schilder; Lauretta Bender's development of the Bender Visual Motor Gestalt Test; and the basic principles of language disorders, including familial patterns, maturation lag, plasticity, and nonfixated…

Family histories of 12 hyperlexic (precocious word reading with little comprehension often associated with autism) children (5-10 years old) were investigated. Results suggested familial tendencies to disorders of language, reading, writing, and spelling in male relatives, along with a high incidence of nonright-handedness. (Author/DB)