Neuregulin 2 Is a Candidate Gene for Autism Spectrum Disorder.

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder with heterogeneous and complex genetic underpinnings. Our previous microarray gene expression profiling identified significantly different neuregulin-2 gene (NRG2) expression between ASD patients and controls. Thus, we aimed to clarify whether NRG2 is a candidate gene associated with ASD. The study consisted of two stages. First, we used real-time quantitative PCR in 20 ASDs and 20 controls to confirm the microarray gene expression profiling results. The average NRG2 gene expression level in patients with ASD (3.23 ± 2.80) was significantly lower than that in the controls (9.27 ± 4.78, p < 0.001). Next, we conducted resequencing of all the exons of NRG2 in a sample of 349 individuals with ASD, aiming to identify variants of the NRG2 associated with ASD. We identified three variants, including two single nucleotide variants (SNVs), IVS3 + 13A > G (rs889022) and IVS10 + 32T > A (rs182642591), and one small deletion at exon 11 of NRG2 (delGCCCGG, rs933769137). Using data from the Taiwan Biobank as the controls, we found no significant differences in allele frequencies of rs889022 and rs182642591 between two groups. However, there is a significant difference in the genotype and allele frequency distribution of rs933769137 between ASDs and controls (p < 0.0001). The small deletion is located in the EGF-like domain at the C-terminal of the NRG2 precursor protein. Our findings suggest that NRG2 might be a susceptibility gene for ASD.

Translational Study of Copy Number Variations in Schizophrenia.

Rare copy number variations (CNVs) are part of the genetics of schizophrenia; they are highly heterogeneous and personalized. The CNV Analysis Group of the Psychiatric Genomic Consortium (PGC) conducted a large-scale analysis and discovered that recurrent CNVs at eight genetic loci were pathogenic to schizophrenia, including 1q21.1, 2p16.3 (NRXN1), 3q29, 7q11.23, 15q13.3, distal 16p11.2, proximal 16p11.2, and 22q11.2. We adopted a two-stage strategy to translate this knowledge into clinical psychiatric practice. As a screening test, we first developed a real-time quantitative PCR (RT-qPCR) panel that simultaneously detected these pathogenic CNVs. Then, we tested the utility of this screening panel by investigating a sample of 557 patients with schizophrenia. Chromosomal microarray analysis (CMA) was used to confirm positive cases from the screening test. We detected and confirmed thirteen patients who carried CNVs at these hot loci, including two patients at 1q21.1, one patient at 7q11.2, three patients at 15q13.3, two patients at 16p11.2, and five patients at 22q11.2. The detection rate in this sample was 2.3%, and the concordance rate between the RT-qPCR test panel and CMA was 100%. Our results suggest that a two-stage approach is cost-effective and reliable in achieving etiological diagnosis for some patients with schizophrenia and improving the understanding of schizophrenia genetics.

High resolution analysis of rare copy number variants in patients with autism spectrum disorder from Taiwan.

Rare genomic copy number variations (CNVs) (frequency <1%) contribute a part to the genetic underpinnings of autism spectrum disorders (ASD). The study aimed to understand the scope of rare CNV in Taiwanese patients with ASD. We conducted a genome-wide CNV screening of 335 ASD patients (299 males, 36 females) from Taiwan using Affymetrix Genome-Wide Human SNP Array 6.0 and compared the incidence of rare CNV with that of 1093 control subjects (525 males, 568 females). We found a significantly increased global burden of rare CNVs in the ASD group compared to the controls as a whole or when the rare CNVs were classified by the size and types of CNV. Further analysis confirmed the presence of several rare CNVs at regions strongly associated with ASD as reported in the literature in our sample. Additionally, we detected several new private pathogenic CNVs in our samples and five patients carrying two pathogenic CNVs. Our data indicate that rare genomic CNVs contribute a part to the genetic landscape of our ASD patients. These CNVs are highly heterogeneous, and the clinical interpretation of the pathogenic CNVs of ASD is not straightforward in consideration of the incomplete penetrance, varied expressivity, and individual genetic background.

Methadone enhances human influenza A virus replication.

Growing evidence has indicated that opioids enhance replication of human immunodeficiency virus and hepatitis C virus in target cells. However, it is unknown whether opioids can enhance replication of other clinically important viral pathogens. In this study, the interaction of opioid agonists and human influenza A/WSN/33 (H1N1) virus was examined in human lung epithelial A549 cells. Cells were exposed to morphine, methadone or buprenorphine followed by human H1N1 viral infection. Exposure to methadone differentially enhanced viral propagation, consistent with an increase in virus adsorption, susceptibility to virus infection and viral protein synthesis. In contrast, morphine or buprenorphine did not alter H1N1 replication. Because A549 cells do not express opioid receptors, methadone-enhanced H1N1 replication in human lung cells may not be mediated through these receptors. The interaction of methadone and H1N1 virus was also examined in adult mice. Treatment with methadone significantly increased H1N1 viral replication in lungs. Our data suggest that use of methadone facilitates influenza A viral infection in lungs and might raise concerns regarding the possible consequence of an increased risk of serious influenza A virus infection in people who receive treatment in methadone maintenance programs.

Elucidating the relationship between work attention performance and emotions arising from listening to music.

BACKGROUND: In addition to demonstrating that human emotions improve work attention performance, numerous studies have also established that music alters human emotions. Given the pervasiveness of background music in the workplace, exactly how work attention, emotions and music listening are related is of priority concern in human resource management. OBJECTIVES: This preliminary study investigates the relationship between work attention performance and emotions arising from listening to music. PARTICIPANTS: Thirty one males and 34 females, ranging from 20-24 years old, participated in this study following written informed consent. METHODS: A randomized controlled trial (RCT) was performed in this study, which consisted of six steps and the use of the standard attention test and emotion questionnaire. RESULTS: Background music with lyrics adversely impacts attention performance more than that without lyrics. Analysis results also indicate that listeners self-reported feeling "loved" while music played that implied a higher score on their work-attention performance. Moreover, a greater ability of music to make listeners feel sad implied a lower score on their work-attention performance. CONCLUSIONS: Results of this preliminary study demonstrate that background music in the workplace should focus mainly on creating an environment in which listeners feel loved or taken care and avoiding music that causes individuals to feel stressed or sad. We recommend that future research increase the number of research participants to enhance the applicability and replicability of these findings.

Dosage of copy number variation at 22q11.2 mediates changes in cognition, social function and brain structure in autism spectrum disorder.

Microdeletion at 22q11.2, a common copy number variation (CNV) noted in neurodevelopmental disorders, may be associated with cognitive impairment. However, cognitive function in individuals with microduplication remains unclear. This work presents the genetic, clinical, and brain structural data of two men out of 335 probands with autistic spectrum disorder (ASD) who had different CNV dosages at 22q11.2, and comparison with their siblings, 55 ASD probands, and 73 controls. Both showed severe autistic symptoms, but the proband with microduplication demonstrated better cognitive functions. Furthermore, different cingulate gyrus volume changes were noted, indicating that the proband with 22q11.2 microduplication had a different pattern of cingulate gyrus structure. Our comprehensive characterization of the behavioral, cognitive, and imaging phenotypes of ASD probands with different CNV dosage at 22q11.2 contribute to how copy number changes at 22q11.2 mediate the phenotypes in ASD, and pave the way for future clinical and functional study on these variants.

Association analysis of the major histocompatibility complex, class II, DQ ß1 gene, HLA-DQB1, with narcolepsy in Han Chinese patients from Taiwan.

BACKGROUND: Narcolepsy is a rare, chronic, disabling neuropsychiatric disorder characterized by excessive daytime sleepiness, cataplexy, hypnagogic hallucinations, sleep paralysis, and abnormal rapid eye movement sleep. It is strongly associated with the HLA-DQB1(∗)06:02 allele in various ethnic groups. Our study aimed to investigate the allelic spectrum of HLA-DQB1 in a sample of Han Chinese patients with narcolepsy and control subjects from Taiwan. METHODS: We determined the genotype of the major histocompatibility complex, class II, DQ ß1 gene, HLA-DQB1, in 72 narcolepsy subjects (44 men, 28 women), including 52 narcolepsy subjects with cataplexy (narcolepsy+cataplexy), 20 narcolepsy subjects without cataplexy (narcolepsy-cataplexy), and 194 control subjects (94 men, 100 women) using a sequence-specific oligonucleotide-probe hybridization technique. RESULTS: We found a strong HLA-DQB1(∗)06:02 association in narcolepsy+cataplexy subjects (odds ratio [OR], 321.4 [95% confidence interval {CI}, 70.7-1461.4]). The association was less prominent in narcolepsy-cataplexy subjects (OR, 6.9 [95% CI, 2.4-20.1]). In addition to the DQB1(∗)06:02, we found that (∗)03:01 also was a predisposing allele (OR, 2.0 [95% CI, 1.1-3.7]) in narcolepsy+cataplexy subjects, though the (∗)06:01 was a predisposing allele (OR, 2.8 [95% CI, 1.2-6.7]) in narcolepsy-cataplexy subjects. Furthermore, we found a significant overrepresentation of DQB1(∗)06:02 homozygotes in narcolepsy+cataplexy subjects. CONCLUSIONS: Our data add further support to the strong association of the HLA-DQB1(∗)06:02 allele with narcolepsy, especially in narcolepsy+cataplexy patients. Our study also indicates additional HLA-DQB1 alleles may modify the presentation of narcolepsy+cataplexy patients, such as DQB1(∗)03:01 and DQB1(∗)06:01 in our study. Our results are limited by the small sample size and can only be considered as preliminary findings.

Deep exon resequencing of DLGAP2 as a candidate gene of autism spectrum disorders.

BACKGROUND: We recently reported a terminal deletion of approximately 2.4 Mb at chromosome 8p23.2-pter in a boy with autism. The deleted region contained the DLGAP2 gene that encodes the neuronal post-synaptic density protein, discs, large (Drosophila) homolog-associated protein 2. The study aimed to investigate whether DLGAP2 is genetically associated with autism spectrum disorders (ASD) in general. METHODS: We re-sequenced all the exons of DLGPA2 in 515 patients with ASD and 596 control subjects from Taiwan. We also conducted bioinformatic analysis and family study of variants identified in this study. RESULTS: We detected nine common single nucleotide polymorphisms (SNPs) and sixteen novel missense rare variants in this sample. We found that AA homozygotes of rs2906569 (minor allele G, alternate allele A) at intron 1 (P = 0.003) and CC homozygotes of rs2301963 (minor allele A, alternate allele C) at exon 3 (P = 0.0003) were significantly over-represented in the patient group compared to the controls. We also found no differences in the combined frequency of rare missense variants between the two groups. Some of these rare variants were predicted to have an impact on the function of DLGAP2 using informatics analysis, and the family study revealed most of the rare missense mutations in patients were inherited from their unaffected parents. CONCLUSIONS: We detected some common and rare genetic variants of DLGAP2 that might have implication in the pathogenesis of ASD, but they alone may not be sufficient to lead to clinical phenotypes. We suggest that further genetic or environmental factors in affected patients may be present and determine the clinical manifestations. TRIAL REGISTRATION: ClinicalTrial.gov, NCT00494754.

Increased gene expression of FOXP1 in patients with autism spectrum disorders.

BACKGROUND: Comparative gene expression profiling analysis is useful in discovering differentially expressed genes associated with various diseases, including mental disorders. Autism spectrum disorders (ASD) are a group of complex childhood-onset neurodevelopmental and genetic disorders characterized by deficits in language development and verbal communication, impaired reciprocal social interaction, and the presence of repetitive behaviors or restricted interests. The study aimed to identify novel genes associated with the pathogenesis of ASD. METHODS: We conducted comparative total gene expression profiling analysis of lymphoblastoid cell lines (LCL) between 16 male patients with ASD and 16 male control subjects to screen differentially expressed genes associated with ASD. We verified one of the differentially expressed genes, FOXP1, using real-time quantitative PCR (RT-qPCR) in a sample of 83 male patients and 83 male controls that included the initial 16 male patients and male controls, respectively. RESULTS: A total of 252 differentially expressed probe sets representing 202 genes were detected between the two groups, including 89 up- and 113 downregulated genes in the ASD group. RT-qPCR verified significant elevation of the FOXP1 gene transcript of LCL in a sample of 83 male patients (10.46 ± 11.34) compared with 83 male controls (5.17 ± 8.20, P = 0.001). CONCLUSIONS: Comparative gene expression profiling analysis of LCL is useful in discovering novel genetic markers associated with ASD. Elevated gene expression of FOXP1 might contribute to the pathogenesis of ASD. CLINICAL TRIAL REGISTRATION: Identifier: NCT00494754.

Identification of two inherited copy number variants in a male with autism supports two-hit and compound heterozygosity models of autism.

Autism is a childhood-onset neurodevelopmental disorder with complex genetic mechanism underlying its etiology. Recent studies revealed that a few single de novo copy number variants of genomic DNA (copy number variants [CNVs]) are pathogenic and causal in some sporadic cases, adding support to the hypothesis that some sporadic autism might be caused by single rare mutation with large clinical effect. In this study, we report the detection of two novel private CNVs simultaneously in a male patient with autism. These two CNVs include a microduplication of ~4.5 Mb at chromosome 4q12-13.1 that was transmitted from his mother and a microdeletion of ~1.8 Mb at 5q32 that was transmitted from his father. Several genes such as LPHN3, POU4F3, SH3RF2, and TCERG1 mapped to these two regions have psychiatric implications. However, the parents had only mild degree of attention deficit symptoms but did not demonstrate any obvious autistic symptoms or psychopathology. Our findings indicate that each of these two CNVs alone may not be pathogenic enough to cause clinical symptoms in their respective carriers, and hence they can be transmitted within each individual family. However, concomitant presence of these two CNVs might result in the clinical phenotypes of the affected patient reported here. Thus, our report of this family may represent an example to show that two hits of CNV and the presence of compound heterozygosity might be important mechanisms underlying the pathogenesis of autism.

Association of HLA-DRB1 alleles and neuropsychological function in autism.

Evidence suggests an association between autism and immune dysfunction. The associations between human lymphocyte antigen (HLA)-A2, B44, DRß1*04 (DR4), C4B, and haplotype B44-SC30-DR4 and autism have been reported in western countries but there is a lack of such information in Asian population. This study aimed to assess the association between HLA-DRB1 allele frequencies and the clinical phenomenology of autism. The sample included 141 participants (male, 87.2%), who were diagnosed with autistic disorder based on clinical assessments and structured interviews using the Chinese version of the Autism Diagnostic Interview-Revised, and 156 healthy controls (male, 38.6%). The HLA-DRB1 alleles were determined by sequencing-based typing method. A subsample of patients (n=39) were assessed for intelligence and neuropsychological functions. The results showed that the pattern of DRB1 allele frequencies was significantly different between patients with autism and the controls (P=0.047). After adjusting for sex by haplotype regression, the frequencies of DR4, DR11, and DR14 were significantly different between patients with autism and healthy controls. In addition, patients with autism and DR4, DR11, or DR14 had different performance on intelligence and neuropsychology tests. Despite a relatively small sample size and a case-control association design, the findings suggest HLA-DRB1 gene might be associated with autism in Han Chinese. The true functional variants associated with autism in our samples remain to be further clarified. It warrants a replication study of a larger family sample and to validate the HLA genetic association with autism and its influence on neuropsychological function.

Association study of the CNS patterning genes and autism in Han Chinese in Taiwan.

Autism is a complex neurodevelopmental disorder with high heritability. Despite different approaches worldwide to identify susceptibility loci or genes for autism spectrum disorders (ASDs), no consistent result has been reported. CNS patterning genes have been recognized as candidate genes for autism based on neuroimage and neuropathology evidence. This study investigated four candidate genes (WNT2, EN2, SHANK3, and FOXP2) by a tag SNP approach in a family-based association study. The trio samples include 1164 subjects from 393 families, including 393 probands (aged 9.1±4.0years; male, 88.6%) diagnosed with autistic disorder (n=373) or Asperger's disorder (n=20) according to the DSM-IV diagnostic criteria and confirmed by the Chinese ADI-R interview. Three tag SNPs of EN2 (7q36), 6 SNPs of WNT2 (7q31-33), 5 SNPs of SHANK3 (22q13.3), 3 SNPs of FOXP2 (7q31) were genotyped. TDT analysis was done to test the association of each tag SNP and haplotype. There was no association with autism for 17 tag SNPs of WNT2, EN2, SHANK3, and FOXP2 based on SNP analyses. Haplotype analyses did not reveal significant association except for the 6 tag SNPs of WNT2 gene showing a significant association on one haplotype composed of rs2896218 and rs6950765 (G-G) (p=0.0095). Other haplotypes composed of rs2896218 and rs6950765 (G-G) were also significantly associated with autism. The present study indicates that SHANK3 may not be a critical gene for the etiology of ASDs in Han Chinese population. Inconsistent findings in EN2 and FOXP2 in the Han Chinese population need further clarification. A haplotype of WNT2 (rs2896218-rs6950765: G-G) is significantly associated with ASDs in our trios samples, this finding warrants further validation by different sample and confirmation by functional study.

Association study of the SLC25A12 gene and autism in Han Chinese in Taiwan.

PURPOSE: Autism is a childhood-onset neurodevelopmental disorder with a strong genetic component in its etiology. Several studies reported that the solute carrier family 25 member A12 (SLC25A12) gene was associated with autism. This study aimed to replicate this finding in a Han Chinese sample from Taiwan using a population-based case-control approach. METHODS: We genotyped two single nucleotide polymorphisms (SNPs, rs2056202 and rs2292813) of the SLC25A12 gene that were previously reported to be associated with autism in 465 patients (402 males and 63 females) and 450 control subjects (227 males and 223 females) from Taiwan. Differences in the genotype, allele, and haplotype frequencies between the two groups were compared. RESULTS: We found no differences in the allele, genotype, or haplotype frequencies of these two SNPs between patients and controls. CONCLUSIONS: Our data do not support that the SLC25A12 gene is associated with autism in our population. The discrepant results of other studies may come from the clinical heterogeneity of patients recruited for studies, or the genetic heterogeneity of autism in different populations.

Lack of evidence to support the glyoxalase 1 gene (GLO1) as a risk gene of autism in Han Chinese patients from Taiwan.

PURPOSE: Previous studies have revealed inconsistent findings regarding the association between the glyoxalase 1 protein (GLO1) gene and autism. This study aimed to replicate the genetic association of the C419A of the GLO1 gene with autism and to perform mutation screening of all the exons of the GLO1 gene in a sample of Han Chinese patients with autism from Taiwan. METHODS: The sample included 272 patients with autism and 310 healthy controls. All the exons and the promoter region of the GLO1 gene were PCR-amplified and sequenced for mutation screening and genotyping. RESULTS: We did not find significant differences of allelic and genotypic frequency distributions of C419A between the autism and control groups. Moreover, we did not identify any other mutations in the exon regions associated with autism in this sample. We discovered two single nucleotide polymorphisms (SNPs) at the 5' untranslated region of the GLO1 gene, designated g.-264T/G and g.-7T/C; however, these two SNPs were not associated with autism in this sample. Further analysis of halplotypes constructed from these 3 SNPs (g.-264T/G, g.-7T/C, and C419A) found no haplotype associated with autism. Our sample size has the power of 0.57 and 0.94 to detect a small effect (0.1) in the genotype and allele frequency distributions at the alpha level of 0.05, respectively. CONCLUSIONS: Our findings suggest that the GLO1 gene is unlikely a major susceptible gene for autism in an ethnic Chinese population from Taiwan.