Dyslexia, left-handedness, and immune disorders.

OBJECTIVE To illuminate a possible three-way association between dyslexia, immune disorders, and left-handedness. Geschwind's, Behan's, and Galaburda's hypotheses have been of special interest in this connection. DESIGN Statistical analysis based on general assessment of the prevalence of the three aforementioned conditions. PARTICIPANTS There were 734 children included from a total of 1165 in grade 6 (about 12 years of age) in the municipality of Stavanger, Norway. SETTING Educational and demographic statistics indicate that the municipality of Stavanger is representative of the national population at large regarding the three conditions examined. MAIN OUTCOME MEASURES A screening test with high reliability and validity was used to assess reading ability. It measured word recognition and phonological decoding. The questionnaires that recorded the students' handedness and immune disorders were filled in by the parents. Handedness was assessed by a Norwegian version of the Oldfield Inventory. A questionnaire concerning allergies and asthma was used to assess the prevalence of immune disorders. RESULTS The bivariate analyses disclosed a significant association between handedness and dyslexia and a significant but weak association between handedness and immune disorders. No significant association was found between dyslexia and immune disorders. A triadic analysis yielded the following: 66.7% of the left-handed dyslexic children had immune disorders (P > .05); 42.1% of the left-handed children with immune disorders had dyslexia (P < .01); and 32% of the dyslexic children with immune disorders were left-handed (P < .05). CONCLUSIONS There seems to be some association between dyslexia, left-handedness, and immune disorders. Of the three factors, handedness seems to be the most important association. The findings lend some support to the one interpretation of the hypotheses of Geschwind, Behan, and Galaburda.

[1]  B. Pennington,et al.  Reading disability, immune disorders and non-right-handedness: Twin and family studies of their relations , 1992, Neuropsychologia.

[2]  D. Bishop.  USING NON‐PREFERRED HAND SKILL TO INVESTIGATE PATHOLOGICAL LEFT‐HANDEDNESS IN AN UNSELECTED POPULATION , 1984, Developmental medicine and child neurology.

[3]  B. Spiegler,et al.  The Autoimmune Disease Systemic Lupus Erythematosus is not Associated with Left-Handedness , 1985, Cortex.

[4]  Bernard J. Ransil,et al.  Associations of handedness with hair color and learning disabilities , 1987, Neuropsychologia.

[5]  M. Pike,et al.  Handedness and Developmental Disorder , 1992 .

[6]  R. C. Oldfield.  The assessment and analysis of handedness: the Edinburgh inventory. , 1971, Neuropsychologia.

[7]  R. Lahita.  Systemic lupus erythematosus: Learning disability in the male offspring of female patients and relationship to laterality , 1988, Psychoneuroendocrinology.

[8]  N. Geschwind,et al.  Cerebral lateralization. Biological mechanisms, associations, and pathology: I. A hypothesis and a program for research. , 1985, Archives of neurology.

[9]  P. Aaron,et al.  Can Reading Disabilities Be Diagnosed Without Using Intelligence Tests? , 1991, Journal of learning disabilities.

[10]  I. Lundberg,et al.  Phonemic Deficits: A Core Symptom of Developmental Dyslexia? , 1989 .

[11]  I. Lundberg,et al.  Patterns of Information Processing Skills and Word Recognition Strategies in Developmental Dyslexia , 1990 .

[12]  K. Hugdahl,et al.  Immune and autoimmune diseases in dyslexic children , 1990, Neuropsychologia.

[13]  K. Stanovich.  Explaining the Differences Between the Dyslexic and the Garden-Variety Poor Reader , 1988, Journal of learning disabilities.

[14]  Richard K. Olson,et al.  Organization, heritability, and remediation of component word recognition and language skills in disabled readers. , 1990 .

[15]  M. Haith,et al.  Left-handedness and immune disorders in familial dyslexics. , 1987, Archives of neurology.

[16]  D. Fulker,et al.  Specific Deficits in Component Reading and Language Skills , 1989, Journal of learning disabilities.

[17]  A. Benton,et al.  Dyslexia: An Appraisal of Current Knowledge , 1978 .

[18]  M. Bryden,et al.  Geschwind's theory of cerebral lateralization: developing a formal, causal model. , 1991, Psychological bulletin.

[19]  Keith E. Stanovich,et al.  Discrepancy definitions of reading disability: Has intelligence led us astray? Reading Research Quar , 1991 .