Left-handedness and immune disorders in familial dyslexics

Area of Science:

• Neurodevelopmental disorders
• Immunology
• Genetics

Background:

• Dyslexia is a common neurodevelopmental disorder affecting reading acquisition.
• Previous research suggests potential links between dyslexia, immune disorders, and handedness, notably Geschwind's hypothesis.
• Genetic linkage studies have identified potential chromosomal regions associated with dyslexia.

Purpose of the Study:

• To investigate the co-occurrence of immune disorders and handedness in individuals with dyslexia within extended families.
• To explore the relationship between immune disorder frequency, handedness, and genetic linkage status in dyslexia.

Main Methods:

• A study involving 87 dyslexic and 86 non-dyslexic individuals from 14 extended families.
• Assessment of handedness (right, mixed, left) and the frequency of autoimmune and allergic disorders.
• Analysis of data in relation to previously established genetic linkage findings for dyslexia on chromosome 15.

Main Results:

• A significant elevation in autoimmune and allergic disorders was observed exclusively in dyslexic individuals.
• No significant difference in the frequency of mixed- or left-handedness was found between dyslexic and non-dyslexic groups.
• The frequency of immune disorders did not correlate with handedness or the presence of genetic linkage to dyslexia.

Conclusions:

• Dyslexia is associated with an increased prevalence of immune disorders, independent of handedness.
• The findings do not support a direct genetic link or shared etiology between dyslexia, immune disorders, and handedness in these families.
• The results provide nuanced insights into the complex interplay of factors potentially underlying dyslexia and immune system variations.