Dyslexia and familial high blood pressure: an observational pilot study.
BACKGROUND
Developmental dyslexia is a neurodevelopmental learning disability characterised by unexpectedly poor reading and unknown aetiology. One hypothesis proposes excessive platelet activating factor, a potent vasodilator, as a contributor, implying that there should be a negative association between dyslexia and high blood pressure (HBP). Since both conditions have a partial genetic basis, this association may be apparent at the familial level.


OBJECTIVE
To test this prediction in dyslexic and non-dyslexic children.


METHODS
Individuals and families with (HBP+) and without (HBP-) a family history of HBP were compared.


RESULTS
Proportionately fewer dyslexics (49/112) than controls (11/12) were HBP+. Families with multiple, all dyslexic children were less likely to be HBP+ (7/16) than those with a non-dyslexic child (11/11). Within families, mean child scores on reading were higher in the HBP+ group (mean 44.3, SE 0.95) than in the HBP- group (mean 40.3, SE 0.87).


CONCLUSIONS
HBP+ family history is associated with better performance on reading. The prediction of a negative association between dyslexic status and familial high blood pressure is therefore confirmed.
Taylor
K
K
University Laboratory of Physiology, Parks Road, Oxford OX1 3PT, UK. kathleen.taylor@physiol.ox.ac.uk
Stein
J
J
D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D004410:Dyslexia / Q000235:genetics*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000235:genetics*; D008297:Male; D016011:Normal Distribution; D010375:Pedigree; D010865:Pilot Projects; D011594:Psychometrics; D011932:Reading