title: Dyslexia and familial high blood pressure: an observational pilot study.
abstract: 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.
authors.affiliation: University Laboratory of Physiology, Parks Road, Oxford OX1 3PT, UK. kathleen.taylor@physiol.ox.ac.uk
authors.forename: K
authors.initials: K
authors.lastname: Taylor
authors.forename: J
authors.initials: J
authors.lastname: Stein
mesh_terms: 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