title: Cardiovascular indices of physiological arousal in boys with fragile X syndrome.
abstract: In this study, the relationship between physiological arousal, as indexed by heart rate variability, was examined in boys with fragile X syndrome (FXS) and typically developing boys matched on chronological age. In addition, the relationship of heart activity to clinical and molecular factors in the group of boys with FXS was examined. Results suggest that boys with FXS have higher levels of heart activity during the passive phases, as reflected in shorter heart periods. This high level of heart activity appears to be due to increased sympathetic activity and reduced parasympathetic activity. Boys with FXS did not display the expected patterns of heart activity in response to phases of increasing challenge, and sympathetic and parasympathetic systems did not appear coordinated in these boys with FXS. Clinical factors may be related to neural regulation of heart activity while molecular factors do not appear to be.
authors.affiliation: Frank Porter Graham, Child Development Center, University of North Carolina, Chapel Hill, NC 27599, USA. Jane_Roberts@unc.edu
authors.forename: J E
authors.initials: JE
authors.lastname: Roberts
authors.forename: M L
authors.initials: ML
authors.lastname: Boccia
authors.forename: D B
authors.initials: DB
authors.lastname: Bailey
authors.forename: D D
authors.initials: DD
authors.lastname: Hatton
authors.forename: M
authors.initials: M
authors.lastname: Skinner
mesh_terms: D017920:Antiporters; D001143:Arousal / Q000502:physiology*; D002318:Cardiovascular Diseases / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology*; D002675:Child, Preschool; D005600:Fragile X Syndrome / Q000150:complications* / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D029701:Saccharomyces cerevisiae Proteins
chemical_list: D017920:Antiporters; D029701:Saccharomyces cerevisiae Proteins; C099946:VCX1 protein, S cerevisiae