| 1 | Schizophr. Res. 2001 Jul 50: 151-7 |
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| PMID | 11439235 |
| Title | Is reduced dermatoglyphic a-b ridge count a reliable marker of developmental impairment in schizophrenia? |
| Abstract | Finger and hand prints are formed during the late first and second trimester of foetal development, after which they remain unchanged. Their expression may be influenced by both genetic and environmental factors. Some studies have suggested that a reduced total finger ridge count (TFRC) and, in particular, a reduce total a-b ridge count (TABRC), may be associated with schizophrenia. To study these two variables in a large, ethnically homogenous sample and to compare our findings with those of other recent studies. Finger and hand prints of 150 people with DSM-III-R schizophrenia were compared with those of 92 healthy controls. Patients had a reduced mean TABRC (P = 0.03) compared with controls. There was a significant (P=0.02) linear trend for lower TABRC and increasing incidence of schizophrenia (ORlineartrend = 1.3; 95%CI1.1-1.7), implying a continuous increase in the risk for schizophrenia with reduction in TABRC. No significant difference between groups was observed for TFRC. These results provide further evidence that dermatoglyphic abnormalities exist in at least some patients with schizophrenia and that the a-b ridge count may be a marker of disruption, probably environmental, that occurs when the developing brain may also be particularly vulnerable to such insult. These findings support the concept that some cases of schizophrenia may be due to adverse intrauterine events. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |
| 2 | Anal. Biochem. 2009 Aug 391: 91-7 |
| PMID | 19464249 |
| Title | Detection of stable reference genes for real-time PCR analysis in schizophrenia and bipolar disorder. |
| Abstract | Gene expression studies using postmortem human brain tissue are a common tool for studying the etiology of psychiatric disorders. Quantitative real-time PCR (qPCR) is an accurate and sensitive technique used for gene expression analysis in which the expression level is quantified by normalization to one or more reference genes. Therefore, accurate data normalization is critical for validating results obtained by qPCR. This study aimed to identify genes that may serve as reference in postmortem dorsolateral-prefrontal cortices (Brodmann's area 46) of schizophrenics, bipolar disorder (BPD) patients, and control subjects. In the exploratory stage of the analysis, samples of four BPD patients, two schizophrenics, and two controls were quantified using the TaqMan Low Density Array endogenous control panel, containing assays for 16 commonly used reference genes. In the next stage, six of these genes (TFRC, RPLP0, ACTB, POLR2a, B2M, and GAPDH) were quantified by qPCR in 12 samples of each clinical group. Expressional stability of the genes was determined by GeNorm and NormFinder. TFRC and RPLP0 were the most stably expressed genes, whereas the commonly used 18S, POLR2a, and GAPDH were the least stable. This report stresses the importance of examining expressional stability of candidate reference genes in the specific sample collection to be analyzed. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |
| 3 | Anal. Biochem. 2009 Aug 391: 91-7 |
| PMID | 19464249 |
| Title | Detection of stable reference genes for real-time PCR analysis in schizophrenia and bipolar disorder. |
| Abstract | Gene expression studies using postmortem human brain tissue are a common tool for studying the etiology of psychiatric disorders. Quantitative real-time PCR (qPCR) is an accurate and sensitive technique used for gene expression analysis in which the expression level is quantified by normalization to one or more reference genes. Therefore, accurate data normalization is critical for validating results obtained by qPCR. This study aimed to identify genes that may serve as reference in postmortem dorsolateral-prefrontal cortices (Brodmann's area 46) of schizophrenics, bipolar disorder (BPD) patients, and control subjects. In the exploratory stage of the analysis, samples of four BPD patients, two schizophrenics, and two controls were quantified using the TaqMan Low Density Array endogenous control panel, containing assays for 16 commonly used reference genes. In the next stage, six of these genes (TFRC, RPLP0, ACTB, POLR2a, B2M, and GAPDH) were quantified by qPCR in 12 samples of each clinical group. Expressional stability of the genes was determined by GeNorm and NormFinder. TFRC and RPLP0 were the most stably expressed genes, whereas the commonly used 18S, POLR2a, and GAPDH were the least stable. This report stresses the importance of examining expressional stability of candidate reference genes in the specific sample collection to be analyzed. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |
| 4 | J Med Assoc Thai 2011 Mar 94: 386-94 |
| PMID | 21560848 |
| Title | Dermatoglyphic traits in Thai schizophrenia patients: a matching case-control study. |
| Abstract | To compare fingerprint patterns, means of dermatoglyphic variables i.e., total finger ridge count, total a-b ridge count, pattern complexity index, and fingerprint pattern asymmetry between patients with schizophrenia and normal controls. A cross-sectional, matching case-control was conducted. Thirty-four males and 34 females with schizophrenia and an equal number of age and sex matched normal controls were selected. Fingerprints and partial palm prints of all of the subjects were obtained using the Automated Inkless Fingerprint Imaging Software and the transparent-adhesive tape technique, respectively. Using paired t-tests (p < 0.05), the cases and controls, males and females separately, were compared for fingerprint pattern asymmetry, total finger ridge counts (TFRC), a-b ridge counts of the right (RABRC), left (LABRC), and both hands (TABRC), and pattern complexity index (PCI). Between cases and controls, neither sex had any significant differences in the mean scores for the pattern asymmetries, TFRC, right-left-ABRC and TABRC. However, the mean scores for PCI were significantly different between the male cases and controls (2.82 vs. 4.94, p = 0 009). Only male patients exhibited average scores for complex patterns (whorls minus arches less than 2), which might be a biomarker for screening of schizophrenia in males. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |
| 5 | Am J Psychiatry 2011 Mar 168: 302-16 |
| PMID | 21285140 |
| Title | Copy number variants in schizophrenia: confirmation of five previous findings and new evidence for 3q29 microdeletions and VIPR2 duplications. |
| Abstract | To evaluate previously reported associations of copy number variants (CNVs) with schizophrenia and to identify additional associations, the authors analyzed CNVs in the Molecular Genetics of schizophrenia study (MGS) and additional available data. After quality control, MGS data for 3,945 subjects with schizophrenia or schizoaffective disorder and 3,611 screened comparison subjects were available for analysis of rare CNVs (<1% frequency). CNV detection thresholds were chosen that maximized concordance in 151 duplicate assays. Pointwise and genewise analyses were carried out, as well as analyses of previously reported regions. Selected regions were visually inspected and confirmed with quantitative polymerase chain reaction. In analyses of MGS data combined with other available data sets, odds ratios of 7.5 or greater were observed for previously reported deletions in chromosomes 1q21.1, 15q13.3, and 22q11.21, duplications in 16p11.2, and exon-disrupting deletions in NRXN1. The most consistently supported candidate associations across data sets included a 1.6-Mb deletion in chromosome 3q29 (21 genes, TFRC to BDH1) that was previously described in a mild-moderate mental retardation syndrome, exonic duplications in the gene for vasoactive intestinal peptide receptor 2 (VIPR2), and exonic duplications in C16orf72. The case subjects had a modestly higher genome-wide number of gene-containing deletions (>100 kb and >1 Mb) but not duplications. The data strongly confirm the association of schizophrenia with 1q21.1, 15q13.3, and 22q11.21 deletions, 16p11.2 duplications, and exonic NRXN1 deletions. These CNVs, as well as 3q29 deletions, are also associated with mental retardation, autism spectrum disorders, and epilepsy. Additional candidate genes and regions, including VIPR2, were identified. Study of the mechanisms underlying these associations should shed light on the pathophysiology of schizophrenia. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |
| 6 | J Psychiatr Res 2011 Nov 45: 1411-8 |
| PMID | 21704324 |
| Title | RT-qPCR study on post-mortem brain samples from patients with major psychiatric disorders: reference genes and specimen characteristics. |
| Abstract | Gene expression studies conducted in post-mortem human brain samples have the potential to identify relevant genes implicated in psychiatric disorders. Although reverse transcription quantitative real-time PCR (RT-qPCR) has emerged as the method of choice for specific gene expression studies, it requires the use of stable reference genes, and it is necessary to control for pre- and post-mortem factors to obtain reliable data. The aim of this study was to identify suitable reference genes and specimen characteristics that can be taken into account when comparing mRNA expression data between post-mortem brain specimens from psychiatric patients and controls. We used a selection of suitably matched occipital cortex specimens from subjects in each of the following groups: schizophrenia (N = 15), bipolar disorder (N = 13), major depressive disorder (N = 15), and control (N = 15). Quantitative and qualitative RNA analyses were performed prior to RT-qPCR and gene expression stability was evaluated with geNorm and NormFinder. We identified GAPDH, RPS17, RPL30, RPLP0, and TFRC as potential reference genes from a sample plate containing 32 candidates commonly used as reference genes. Further analyses of these 5 genes highlighted that 1) they are suitable reference genes for RT-qPCR studies in these post-mortem brain samples from psychiatric patients, and 2) the RNA quality index is highly correlated with gene expression values (r = -0.681, p < 0.0001). In addition to controlling for pre- and post-mortem factors and selecting stable reference genes for normalization, sample sets should be matched with regard to RNA quality. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |
| 7 | World J Psychiatry 2013 Sep 3: 57-61 |
| PMID | 24255876 |
| Title | New findings in the genetics of schizophrenia. |
| Abstract | New findings in schizophrenia genetics are based on genome-wide association studies (GWAS), research into DNA copy number variations (CNVs), and endophenotypes. More than 70 genes have recently been suspected to be involved in the genetic background of schizophrenia based on the GWAS´s results. They are typically related to neurodevelopment/neuroplasticity, immunology and neuroendocrinology. Nevertheless, for many detected genes their possible relationship to schizophrenia etiopathogenesis is still unknown. The CNVs at genome loci 1q21.1 (candidate gene e.g., PRKAB2), 2p16.3 (candidate gene e.g., NRXN1), 3q29 (candidate genes e.g., BDH1, DLG1, PAK2 or TFRC), 15q11.2 (candidate gene e.g., CYFIP1), 15q13.3 (candidate gene e.g., CHRNA7), 16p13.1 (candidate genes e.g.,NTAN1 or NDE1) and 22q11.2 (candidate genes e.g., COMT, GSTT2 or PRODH) were associated with schizophrenia most frequently. Genetic research of schizophrenia endophenotypes, usually neurophysiological, neuromotoric, neurocognitive, neuroanatomical, neurological or personality-related, will help us to discover the role of relevant genes in the pathogenesis of schizophrenia. It is also necessary to integrate knowledge from other research platforms in schizophrenia, like epigenetics, studies of gene-environment interactions, transcriptomics, proteomics, metabolomics, neuroimaging and psychopathology. A better knowledge of the genetic background of schizophrenia can lead to changes in the treatment, prevention and genetic counselling. It may also reduce stigma in this severe mental disorder. |
| SCZ Keywords | schizophrenia, schizophrenic, schizophrenics |