Affiliations: Department of Biochemistry, Cankiri Karatekin
University, School of Health, Cankiri 18200, Turkey. Tel.: +90 544 613 4999; Fax: +90 376 212 00 75;
E-mail: emrah333@hotmail.com
Abstract: There is increasing evidence that biochemistry, genetics and
cognitive deficits play a part in the etiology of developmental dyslexia (DD).
The developmental dyslexia\reading disability (RD) that is part of a larger
heterogeneous group of learning disorders, and characterized by unexpected
problems in academic performance, despite average intelligence. However,
controversy still surrounds both the identification and management of this
condition, and while its etiology is recognized as being complex and
multifactorial, yet little progress has been made in elucidating predisposing
factors at the biological level. The purpose of this review is to explore the
possibility of dyslexia that falls within biochemical and cognitive spectrum of
disorder. Based on the biochemical evidence, there is a necessity for further
research into the role of fatty acids in developmental dyslexia that
contributed with an abnormal metabolism of HUFA in fetal brain development, or
the maintenance of normal brain function. Currently, the molecular geneticists
have been seeking to identify the actual genes underlying developmental
dyslexia. Nine loci were found to be associated with susceptibility to dyslexia
(DYX1 to DYX9). Those have contained important four candidate genes associated
with dyslexia that would aid in distinguishing between children whose reading
problems are caused primarily by cognitive deficits with biological origin.
Accordingly, the cognitive deficits of dyslexia will be presented in the
domains of phonological, auditory processing, visual, magnocellular and
automaticity/cerebellar deficit theories. Understanding the biochemical and
cognitive basis of dyslexia may help us plan our future research.
