Altered subcortical and cortical brain morphology in adult women with 47,XXX: a 7-Tesla magnetic resonance imaging study

Triple X syndrome: Psychiatric disorders and impaired social functioning as a risk factor

BACKGROUND

Women with triple X syndrome (TXS) have an extra X chromosome. TXS appeared to be associated with psychiatric disorders in biased or underpowered studies.

AIM

This study aims to describe the prevalence of psychiatric disorders in adults with TXS in a relatively large and less biased group of participants.

METHOD

In this cross-sectional study, data were collected from 34 women with TXS (mean age = 32.9; s.d. = 13.1) and 31 controls (mean age = 34.9; s.d. = 13.7). Psychiatric disorders were assessed using the MINI International Neuropsychiatric Interview (MINI) and the adult behavior checklist (ABCL). Trait and state anxiety were assessed using the State-Trait Anxiety Inventory.

RESULTS

In the TXS group, MINI results showed a higher prevalence of major depressive episodes (43.3%), psychotic disorders (29.4%), and suicidality (23.5%). Only 50% of the TXS group earned a normal score for the total syndrome score using the ABCL. In addition, levels of trait anxiety were higher in the TXS group. Only three women in each group received psychotropic medication. Impaired social functioning appeared to represent a major risk factor in TXS as regards psychotic, affective disorders, trait anxiety, and low self-esteem.

CONCLUSIONS

Women with TXS are vulnerable to developing psychiatric disorders, and women with both TXS and impaired social functioning are even more vulnerable.

Resting-state functional connectivity in adults with 47,XXX: a 7 Tesla MRI study

Triple X syndrome is a sex chromosomal aneuploidy characterized by the presence of a supernumerary X chromosome, resulting in a karyotype of 47,XXX in affected females. It has been associated with a variable cognitive, behavioral, and psychiatric phenotype, but little is known about its effects on brain function. We therefore conducted 7 T resting-state functional magnetic resonance imaging and compared data of 19 adult individuals with 47,XXX and 21 age-matched healthy control women using independent component analysis and dual regression. Additionally, we examined potential relationships between social cognition and social functioning scores, and IQ, and mean functional connectivity values. The 47,XXX group showed significantly increased functional connectivity of the fronto-parietal resting-state network with the right postcentral gyrus. Resting-state functional connectivity (rsFC) variability was not associated with IQ and social cognition and social functioning deficits in the participants with 47,XXX. We thus observed an effect of a supernumerary X chromosome in adult women on fronto-parietal rsFC. These findings provide additional insight into the role of the X chromosome on functional connectivity of the brain. Further research is needed to understand the clinical implications of altered rsFC in 47,XXX.

The Relationships between Dopaminergic, Glutamatergic, and Cognitive Functioning in 22q11.2 Deletion Syndrome: A Cross-Sectional, Multimodal 1H-MRS and 18F-Fallypride PET Study

BACKGROUND

Individuals with 22q11.2 deletion syndrome (22q11DS) are at increased risk of developing psychosis and cognitive impairments, which may be related to dopaminergic and glutamatergic abnormalities. Therefore, in this exploratory study, we examined the association between dopaminergic and glutamatergic functioning in 22q11DS. Additionally, the associations between glutamatergic functioning and brain volumes in 22q11DS and healthy controls (HC), as well as those between dopaminergic and cognitive functioning in 22q11DS, were also examined.

METHODS

In this cross-sectional, multimodal imaging study, glutamate, glutamine, and their combined concentration (Glx) were assessed in the anterior cingulate cortex (ACC) and striatum in 17 22q11DS patients and 20 HC using 7T proton magnetic resonance spectroscopy. Ten 22q11DS patients also underwent 18F-fallypride positron emission tomography to measure dopamine D2/3 receptor (D2/3R) availability in the ACC and striatum. Cognitive performance was assessed with the Cambridge Neuropsychological Test Automated Battery.

RESULTS

No significant associations were found between ACC or striatal (1) glutamate, glutamine, or Glx concentrations and (2) D2/3R availability. In HC but not in 22q11DS patients, we found a significant relationship between ACC volume and ACC glutamate, glutamine, and Glx concentration. In addition, some aspects of cognitive functioning were significantly associated with D2/3R availability in 22q11DS. However, none of the associations remained significant after Bonferroni correction.

CONCLUSIONS

Although our results did not reach statistical significance, our findings suggest an association between glutamatergic functioning and brain volume in HC but not in 22q11DS. Additionally, D2/3R availability seems to be related to cognitive functioning in 22q11DS. Studies in larger samples are needed to further elucidate our findings.