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Psychophysiological markers of vulnerability to psychopathology in men with an extra X chromosome (XXY).

van Rijn S, Swaab H, Magnée M, van Engeland H, Kemner C - PLoS ONE (2011)

Bottom Line: Also, reduced sensory gating in individuals with KS was suggested by significantly reduced prepulse inhibition of the startle response (PPI) (effect size 1.6).No abnormalities were found in suppression of the P50 (effect size 0.6).In sum, studying individuals with KS may prove to be an avenue of research leading to new hypotheses and insights into "at risk" pathways to psychopathology.

View Article: PubMed Central - PubMed

Affiliation: Clinical Child and Adolescent Studies, Leiden University, Leiden, The Netherlands. srijn@fsw.leidenuniv.nl

ABSTRACT
Studying genetically defined syndromes associated with increased risk for psychopathology may help in understanding neurodevelopmental mechanisms related to risk for psychopathology. Klinefelter syndrome (47,XXY) is one of the most common sex chromosomal aneuploidies (1 in 650 male births) and associated with increased vulnerability for psychopathology, including psychotic symptoms. Yet, it remains unknown whether this increased risk is associated with underlying psychophysiological mechanisms that are typically deficient in individuals with psychotic disorders. The present study assessed three "classic" psychophysiological markers of psychosis in Klinefelter syndrome (KS): smooth pursuit eye movements (SPEM), prepulse inhibition (PPI) and P50 suppression. Fourteen adults with KS and 15 non-clinical adults participated in the study. Data on SPEM (reflecting visuo-motor control) as well as PPI and P50 suppression (reflecting sensory gating) were collected. Dysfunctions in SPEM were observed in individuals with KS, with less smooth pursuit as expressed in lower position gain. Also, reduced sensory gating in individuals with KS was suggested by significantly reduced prepulse inhibition of the startle response (PPI) (effect size 1.6). No abnormalities were found in suppression of the P50 (effect size 0.6). We speculate that impairments in these psychophysiological mechanisms may reflect core brain dysfunctions that may also mediate the described increased vulnerability for psychotic symptoms in KS. Although speculative, such deficit specific, rather than disorder specific, psychophysiological dysfunctions in KS might convey vulnerability to other types of psychopathology as well. As KS already can be diagnosed prenatally, the predictive value of childhood impairments in prepulse inhibition and smooth pursuit for development of psychopathology later in life could be assessed. In sum, studying individuals with KS may prove to be an avenue of research leading to new hypotheses and insights into "at risk" pathways to psychopathology.

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Auditory evoked potentials in the XXY group in response to the conditioning and testing stimulus in the P50 gating paradigm.
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pone-0020292-g006: Auditory evoked potentials in the XXY group in response to the conditioning and testing stimulus in the P50 gating paradigm.

Mentions: One subject in the Klinefelter group showed a T/C ratio at P50 of 3.5 standard deviations above group mean and was therefore excluded from analysis of P50 peaks. There was no significant main effect of group on suppression of the P50 or N100 (see figures 5 and 6 for averaged signals). In other words, there was no difference between the mean T/C ratio at P50 in the Klinefelter group (0.40, SD 0.35) as compared to the control group (0.62, SD 0.99), F(1,26) = 0.56, p = 0.46. Although not significant, the effect size (cohen's d) was 0.63, i.e. the distance between the group means was 0.63 standard deviations. Also, there was no significant main effect of age or IQ.


Psychophysiological markers of vulnerability to psychopathology in men with an extra X chromosome (XXY).

van Rijn S, Swaab H, Magnée M, van Engeland H, Kemner C - PLoS ONE (2011)

Auditory evoked potentials in the XXY group in response to the conditioning and testing stimulus in the P50 gating paradigm.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3105055&req=5

pone-0020292-g006: Auditory evoked potentials in the XXY group in response to the conditioning and testing stimulus in the P50 gating paradigm.
Mentions: One subject in the Klinefelter group showed a T/C ratio at P50 of 3.5 standard deviations above group mean and was therefore excluded from analysis of P50 peaks. There was no significant main effect of group on suppression of the P50 or N100 (see figures 5 and 6 for averaged signals). In other words, there was no difference between the mean T/C ratio at P50 in the Klinefelter group (0.40, SD 0.35) as compared to the control group (0.62, SD 0.99), F(1,26) = 0.56, p = 0.46. Although not significant, the effect size (cohen's d) was 0.63, i.e. the distance between the group means was 0.63 standard deviations. Also, there was no significant main effect of age or IQ.

Bottom Line: Also, reduced sensory gating in individuals with KS was suggested by significantly reduced prepulse inhibition of the startle response (PPI) (effect size 1.6).No abnormalities were found in suppression of the P50 (effect size 0.6).In sum, studying individuals with KS may prove to be an avenue of research leading to new hypotheses and insights into "at risk" pathways to psychopathology.

View Article: PubMed Central - PubMed

Affiliation: Clinical Child and Adolescent Studies, Leiden University, Leiden, The Netherlands. srijn@fsw.leidenuniv.nl

ABSTRACT
Studying genetically defined syndromes associated with increased risk for psychopathology may help in understanding neurodevelopmental mechanisms related to risk for psychopathology. Klinefelter syndrome (47,XXY) is one of the most common sex chromosomal aneuploidies (1 in 650 male births) and associated with increased vulnerability for psychopathology, including psychotic symptoms. Yet, it remains unknown whether this increased risk is associated with underlying psychophysiological mechanisms that are typically deficient in individuals with psychotic disorders. The present study assessed three "classic" psychophysiological markers of psychosis in Klinefelter syndrome (KS): smooth pursuit eye movements (SPEM), prepulse inhibition (PPI) and P50 suppression. Fourteen adults with KS and 15 non-clinical adults participated in the study. Data on SPEM (reflecting visuo-motor control) as well as PPI and P50 suppression (reflecting sensory gating) were collected. Dysfunctions in SPEM were observed in individuals with KS, with less smooth pursuit as expressed in lower position gain. Also, reduced sensory gating in individuals with KS was suggested by significantly reduced prepulse inhibition of the startle response (PPI) (effect size 1.6). No abnormalities were found in suppression of the P50 (effect size 0.6). We speculate that impairments in these psychophysiological mechanisms may reflect core brain dysfunctions that may also mediate the described increased vulnerability for psychotic symptoms in KS. Although speculative, such deficit specific, rather than disorder specific, psychophysiological dysfunctions in KS might convey vulnerability to other types of psychopathology as well. As KS already can be diagnosed prenatally, the predictive value of childhood impairments in prepulse inhibition and smooth pursuit for development of psychopathology later in life could be assessed. In sum, studying individuals with KS may prove to be an avenue of research leading to new hypotheses and insights into "at risk" pathways to psychopathology.

Show MeSH
Related in: MedlinePlus