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. 2019 Jan 11:9:2669.
doi: 10.3389/fpsyg.2018.02669. eCollection 2018.

Neurobiological Sex Differences in Developmental Dyslexia

Anthony J Krafnick  1 , Tanya M Evans  2
Affiliations

Neurobiological Sex Differences in Developmental Dyslexia

Anthony J Krafnick et al. Front Psychol. .

Abstract

Understanding sex differences at the neurobiological level has become increasingly crucial in both basic and applied research. In the study of developmental dyslexia, early neuroimaging investigations were dominated by male-only or male-dominated samples, due at least in part to males being diagnosed more frequently. While recent studies more consistently balance the inclusion of both sexes, there has been little movement toward directly characterizing potential sex differences of the disorder. However, a string of recent work suggests that the brain basis of dyslexia may indeed be different in males and females. This potential sex difference has implications for existing models of dyslexia, and would inform approaches to the remediation of reading difficulties. This article reviews recent evidence for sex differences in dyslexia, discusses the impact these studies have on the understanding of the brain basis of dyslexia, and provides a framework for how these differential neuroanatomical profiles may develop.

Keywords: dyslexia; genetics; neuroanatomy; reading; sex differences.

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Figures

FIGURE 1
FIGURE 1
Literature of sex differences over time. Searches via PubMed. (A) Results for search parameters: (Sex differences; OR Gender differences). (B) Results for search parameters: (Sex differences; OR Gender differences) AND brain. (C) Results for search parameters: (Sex differences; OR Gender differences) AND dyslexia. Note scale difference for y axes across panels.
FIGURE 2
FIGURE 2
Framework for sex differences in dyslexia brain anatomy. (A) Hypothetical relationship between gray matter volume and fetal testosterone. At baseline, males (dotted blue line) may have greater volume of sensory/motor structures (solid orange line) and lesser volume within traditional language network regions (solid green line) compared to females (dotted red line), mediated by fetal testosterone. Adapted with permission from doctoral dissertation (Evans, 2013). (B) Hypothetical overlap between volumetric reductions the language network in males with ectopias observed post mortem. Reduced GMV and neural migration errors may overlap in the language network of males with dyslexia.
See this image and copyright information in PMC

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