Association between forkhead-box P2 gene polymorphism and clinical symptoms in chronic schizophrenia in a Chinese population

The Brain Connectome for Chinese Reading

Chinese, as a logographic language, fundamentally differs from alphabetic languages like English. Previous neuroimaging studies have mainly focused on alphabetic languages, while the exploration of Chinese reading is still an emerging and fast-growing research field. Recently, a growing number of neuroimaging studies have explored the neural circuit of Chinese reading. Here, we summarize previous research on Chinese reading from a connectomic perspective. Converging evidence indicates that the left middle frontal gyrus is a specialized hub region that connects the ventral with dorsal pathways for Chinese reading. Notably, the orthography-to-phonology and orthography-to-semantics mapping, mainly processed in the ventral pathway, are more specific during Chinese reading. Besides, in addition to the left-lateralized language-related regions, reading pathways in the right hemisphere also play an important role in Chinese reading. Throughout, we comprehensively review prior findings and emphasize several challenging issues to be explored in future work.

Sexual dimorphism in the relationship between Forkhead-Box P2 and BMI with cognitive deficits in schizophrenia

FOXP2, cognitive deficits, and schizophrenia are associated with neurodegenerative pathophyisiology. Mounting evidence suggests that body mass index (BMI) and FOXP2 may contribute to cognitive deficits in schizophrenia. However, the sex difference in the contribution of FOXP2 and BMI, as well as their potential interaction with cognitive deficits in schizophrenia, have not been investigated. A total of 867 schizophrenia patients and 402 controls were recruited. Cognitive function was assessed using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). The polymorphism rs10447760 of the FOXP2 gene was genotyped. Male schizophrenia patients had superior language performance compared to female patients (F = 17.83; pBonferroni < 0.0001). BMI was positively associated with language scores in male patients with schizophrenia (ß = 0.60, t = 3.30, p = 0.001), as well as in patients with schizophrenia who carried the FOXP2 rs10447760 CC genotype (ß = 0.53, t = 3.16, p = 0.002). Interestingly, this association was only found in male patients with schizophrenia who also carried the FOXP2 rs10447760 CC genotype (ß = 0.63, t = 3.44, p = 0.001). Our study reveals a sex difference in the language deficits of schizophrenia patients and shows sexual dimorphism in the contribution of FOXP2, BMI, and their interaction to cognitive deficits in patients with schizophrenia.

Association between clinical symptoms and apolipoprotein A1 or apolipoprotein B levels is regulated by apolipoprotein E variant rs429358 in patients with chronic schizophrenia

BACKGROUND

The apolipoprotein E (ApoE) gene polymorphisms are correlated with blood lipid levels and several neuropsychiatric symptoms. Therefore, this study aimed to examine whether the ApoE rs429358 affected the development and clinical symptoms of schizophrenia and to explore the relationship between apolipoproteins levels and clinical symptoms.

METHODS

The ApoE rs429358 was genotyped using a case-control design. The Positive and Negative Syndrome Scale (PANSS) was employed to evaluate the psychopathology of all patients.

RESULTS

A total of 637 patients with schizophrenia and 467 healthy controls were recruited. We found no significant differences in the genotype and allele distribution between the patient and control groups. A significant correlation between PANSS negative symptoms and ApoA1 levels (p = 0.048) or ApoB levels (p = 0.001) was found in patients with schizophrenia, which was also confirmed by linear regression analyses (p = 0.048 vs. p = 0.001). Interestingly, only in the T homozygote group, ApoA1 and ApoB levels were predictors of the PANSS negative symptom score (p = 0.008 vs. p = 0.012), while in the C allele carrier group, no correlation was observed.

CONCLUSIONS

This study found that the levels of ApoA1 and ApoB were negatively associated with negative symptoms of patients with schizophrenia. Furthermore, the association between ApoA1 or ApoB levels and psychopathology of schizophrenia was regulated by ApoE rs429358.

Dissecting the neurobiology of linguistic disorganisation and impoverishment in schizophrenia

Schizophrenia provides a quintessential disease model of how disturbances in the molecular mechanisms of neurodevelopment lead to disruptions in the emergence of cognition. The central and often persistent feature of this illness is the disorganisation and impoverishment of language and related expressive behaviours. Though clinically more prominent, the periodic perceptual distortions characterised as psychosis are non-specific and often episodic. While several insights into psychosis have been gained based on study of the dopaminergic system, the mechanistic basis of linguistic disorganisation and impoverishment is still elusive. Key findings from cellular to systems-level studies highlight the role of ubiquitous, inhibitory processes in language production. Dysregulation of these processes at critical time periods, in key brain areas, provides a surprisingly parsimonious account of linguistic disorganisation and impoverishment in schizophrenia. This review links the notion of excitatory/inhibitory (E/I) imbalance at cortical microcircuits to the expression of language behaviour characteristic of schizophrenia, through the building blocks of neurochemistry, neurophysiology, and neurocognition.

Molecular networks of the FOXP2 transcription factor in the brain

The discovery of the FOXP2 transcription factor, and its implication in a rare severe human speech and language disorder, has led to two decades of empirical studies focused on uncovering its roles in the brain using a range of in vitro and in vivo methods. Here, we discuss what we have learned about the regulation of FOXP2, its downstream effectors, and its modes of action as a transcription factor in brain development and function, providing an integrated overview of what is currently known about the critical molecular networks.

FOXP2 expression and gray matter density in the male brains of patients with schizophrenia

Common genetic variants of FOXP2 may contribute to schizophrenia vulnerability, but controversial results have been reported for this proposal. Here we evaluated the potential impact of the common FOXP2 rs2396753 polymorphism in schizophrenia. It was previously reported to be part of a risk haplotype for this disease and to have significant effects on gray matter concentration in the patients. We undertook the first examination into whether rs2396753 affects the brain expression of FOXP2 and a replication study of earlier neuroimaging findings of the influence of this genetic variant on brain structure. FOXP2 expression levels were measured in postmortem prefrontal cortex samples of 84 male subjects (48 patients and 36 controls) from the CIBERSAM Brain and the Stanley Foundation Array Collections. High-resolution anatomical magnetic resonance imaging was performed on 79 male subjects (61 patients, 18 controls) using optimized voxel-based morphometry. We found differences in FOXP2 expression and brain morphometry depending on the rs2396753, relating low FOXP2 mRNA levels with reduction of gray matter density. We detected an interaction between rs2396753 and the clinical groups, showing that heterozygous patients for this polymorphism have gray matter density decrease and low FOXP2 expression comparing with the heterozygous controls. This study shows the importance of independent replication of neuroimaging genetic studies of FOXP2 as a candidate gene in schizophrenia. Furthermore, our results suggest that the FOXP2 rs2396753 affects mRNA levels, thus providing new knowledge about its significance as a potential susceptibility polymorphism in schizophrenia.

Neuregulin 3 rs10748842 polymorphism contributes to the effect of body mass index on cognitive impairment in patients with schizophrenia

There is evidence that obesity or higher body mass index is correlated with cognitive impairment in schizophrenia. Recent studies have demonstrated that genetic risk factors, such as the NRG3, are correlated with both elevated BMI and reduced cognitive function. In present study, we aimed to determine whether possession of the NRG3 rs10748842 influences the correlation between elevated BMI and reduced cognitive ability in schizophrenia. To our knowledge, this has never been examined before. A total of 625 inpatients with schizophrenia and 400 controls were recruited. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was performed to assess cognitive function. We used multiple analysis of covariance (MANCOVA), analyses of covariance (ANCOVA), Pearson correlations, partial correlations, and multivariate regression analysis to test the influence of NRG3 rs10748842 on the aforementioned variables. All RBANS five sub-scores and total score were lower in patients than those in controls (all p < 0.001). Patients carrying NRG3 rs10748842 TC + CC heterozygous genotype had lower attention score compared to TT homozygous genotype (adjusted F = 4.77, p = 0.029). BMI was positively associated with language score in patients (β = 0.387, t = 2.59, p = 0.01). Interestingly, we further found positive association between BMI and language score in TT carriers (partial correlations: r = 0.13, adjusted p = 0.004; multivariate regression: β = 0.42, t = 2.66, p = 0.008), but not in CT + CC carrier (p > 0.05). Our study demonstrated that NRG3 rs10748842 was associated with cognitive impairments, especially attention performance in schizophrenia. Moreover, NRG3 rs10748842 altered the effect of BMI on cognitive impairments as measured by the RBANS language score in chronic patients with schizophrenia.

Genetic Intersections of Language and Neuropsychiatric Conditions

PURPOSE OF REVIEW

To better understand the shared basis of language and mental health, this review examines the behavioral and neurobiological features of aberrant language in five major neuropsychiatric conditions. Special attention is paid to genes implicated in both language and neuropsychiatric disorders, as they reveal biological domains likely to underpin the processes controlling both.

RECENT FINDINGS

Abnormal language and communication are common manifestations of neuropsychiatric conditions, and children with impaired language are more likely to develop psychiatric disorders than their peers. Major themes in the genetics of both language and psychiatry include master transcriptional regulators, like FOXP2; key developmental regulators, like AUTS2; and mediators of neurotransmission, like GRIN2A and CACNA1C.

NRG3 contributes to cognitive deficits in chronic patients with schizophrenia

BACKGROUND

Cognitive deficit is a fundamental trait of schizophrenia, but its mecwhanisms remain unknown. The neuregulin 3 (NRG3) gene, involving in neuronal function, has been considered to be associated with schizophrenia and cognition. However, no study has investigated the effects of NRG3 polymorphism on cognitive deficits in a large sample of the patients with schizophrenia.

METHODS

A total of 1112 schizophrenia patients and 423 controls were recruited and genotyped with NRG3 rs10748842. Among them, 864 patients and 403 controls were assessed for cognition through the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). SHEsis was applied and followed by logistic regression analysis. The models of analyses of covariance (ANCOVA) were constructed to examine the effects of NRG3 rs10748842 on cognitive deficits.

RESULTS

No differences in NRG3 rs10748842 allele and genotype were found between patients and controls (both p > 0.05). With the exception of Visuospatial/construction, the other RBANS scores were significantly lower in patients compared to controls after adjusting for gender and education (all p < 0.001). Interestingly, we found that NRG3 rs10748842 was associated with cognitive deficit in schizophrenia, showing that patients carrying C allele had lower attention and total scores than those with TT genotype (both p < 0.05).

CONCLUSION

NRG3 rs10748842 may not confer susceptibility to schizophrenia, but may be more closely associated with cognitive deficit, especially attention performance in chronic schizophrenia.

FOXP2 contributes to the cognitive impairment in chronic patients with schizophrenia

The forkhead-box P2 (FOXP2), involving in language and memory function, has been identified as susceptibility to schizophrenia. However, no study examined the role of FOXP2 on cognitive impairment in schizophrenia. Total 1106 inpatients with schizophrenia and 404 controls were recruited and genotyped. Among them, 867 patients and 402 controls were assessed through the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). SHEsis software was used to investigate the association of FOXP2 rs10447760 with schizophrenia, followed by logistic regression. The model of covariance (ANCOVA) and multivariate analysis were conducted to investigate the effect of FOXP2 rs10447760 on cognitive impairment in schizophrenia. No differences in the genotypic and allelic frequencies of the FOXP2 rs10447760 were found between patients and controls (both p> 0.05). Except for the visuospatial/constructional score (p > 0.05), other five RBANS scores were lower in patients compared to controls (all p < 0.0001). Interestingly, we found immediate memory score was lower in patients carrying genotype CT compared to genotype CC (F=5.19, p=0.02), adjusting for confounding data. Our study suggested that FOXP2 rs10447760 has no effect on the susceptibility to schizophrenia, while it may be associated with its cognitive impairment, especially immediate memory in chronic schizophrenia.

No association between FOXP2 rs10447760 and schizophrenia in a replication study of the Chinese Han population

BACKGROUND

Schizophrenia (SCZ) is a severe and heritable psychiatric disorder, and previous studies have shown that regulation of the forkhead-box P2 gene (FOXP2) may play a role in schizophrenia. Moreover, just a few studies have identified a single nucleotide polymorphism (SNP) rs10447760 within the gene that was a risk variant for SCZ in the Chinese Han population.

METHODS

To examine whether the variant in the FOXP2 gene contributes toward SCZ susceptibility, we carried out an association analysis of the SNP rs10447760 of the FOXP2 gene in a case-control study (1405 cases, 1137 controls) from China.

RESULTS

We identified no association of rs10447760 in the FOXP2 gene with SCZ (all P>0.05). In addition, a meta-analysis indicated that the SNP rs10447760 was not associated with susceptibility to SCZ in Han Chinese populations (pooled odds ratio=1.44, 95% confidence interval: 0.63-3.31, P=0.39).

CONCLUSION

Thus, our results did not support the association between FOXP2 rs10447760 and schizophrenia in a Chinese Han population, and large-scale genetic replication studies with different racial and geographic origins are required in the future.

Interstitial deletion within 7q31.1q31.3 in a woman with mild intellectual disability and schizophrenia

We report the case of a Japanese woman with an interstitial deletion within the 7q31.1q31.3 region, she presented with mild intellectual disability since infancy, and later developed characteristic psychiatric manifestations, including abnormal behavior, delusions, and hallucinations. She was diagnosed with paranoid schizophrenia (F20.0, International Statistical Classification of Diseases and Related Health Problems 10th Revision). Array comparative genomic hybridization examination revealed the deletion involving several important genes for neurodevelopment. Particularly, FOXP2, DOCK4, MET, and WNT2 in this region are suggested to be related to language impairment, autistic disorders, and cognitive disorders, via the WNT pathway. In addition, the WNT signal pathway has been suggested to be implicated in the pathogenesis of psychiatric disorders such as schizophrenia and bipolar disorder. However, there is no case report regarding schizophrenia associated with a 7q31 microdeletion. We suspect that the disruptions of these one or plural genes among the interstitial deletion of 7q31.1q31.3 may be involved in the development of schizophrenia in this woman. This is the first report on schizophrenia associated with a 7q31 microdeletion.