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Ming T Tsuang

Publications and source records attributed to Ming T Tsuang.

At least 19 recordsLinked to original sources

Schizophrenia is not associated with the functional candidate gene ERBB3: results from a case-control study.

Increasing evidence has supported the hypothesis of a neurodevelopmental component in the etiology of schizophrenia. Recently, several independent microarray gene expression studies have revealed downregulated expression of myelin-related genes in the postmortem brains of schizophrenia patients. Complete myelination of the cortex has been observed to occur in late adolescence and early adulthood, which is typically the age of onset of schizophrenia. ERBB3 is a gene which has not only been found to be downregulated in schizophrenia simultaneously in three microarray studies, but also is a strong candidate because of its potential role in neurodevelopment as a receptor of NRG1. Therefore, we performed association analysis of seven nonsynonymous SNPs in this gene. Two SNPs in ERBB3 (rs773123 and rs2271188) were polymorphic in our samples, neither of which showed significant evidence of association with the illness (P = 0.639 and 0.561, respectively). Because replication across such studies is notoriously difficult, the microarray evidence implicating ERBB3 still strongly supports some role of this gene in schizophrenia. However, our failure to find genetic association suggests that the differential expression of ERBB3 in schizophrenia may be environmentally driven, or involve cis- or trans-acting genetic factors beyond the boundaries of the gene itself.

Adolescent↗

Neuroanatomic substrates of sex differences in language dysfunction in schizophrenia: a pilot study.

OBJECTIVE: This pilot study investigated whether our previous findings of disrupted normal sexual brain dimorphisms in language-associated regions in schizophrenia were linked with our previously reported sex differences in language dysfunction in schizophrenia. METHOD: Nineteen adults with schizophrenia and 15 normal comparisons were tested on phonology, semantics and grammar and underwent structural MRI. RESULTS: Among males, left hippocampal and left planum temporale (PT) abnormalities were associated with phonological, semantic and grammar deficits, accounting for 17-52% and 27-33%, respectively, of variance in diagnostic group differences. Anterior cingulate gyrus was significantly associated with semantics. Among females, right Heschl's Gyrus (HG) and left PT were significantly associated with phonology, right HG with semantics and grammar and right hippocampus with semantics. CONCLUSIONS: These preliminary findings suggest disrupted sexual brain dimorphisms in schizophrenia are associated with sex-specific language deficits, and left hippocampal abnormalities, in particular, contribute to language dysfunction among men. Abnormalities in right cortical temporal regions showed stronger associations with language dysfunction among females.

Adolescent↗

Genome-wide linkage scan of schizophrenia: a cross-isolate study.

Genetic isolates are exceptional resources for the detection of susceptibility genes for complex diseases because of the potential reduction in genetic and clinical heterogeneity. However, the outcome of these mapping efforts is dependent upon the demographic history of a given isolated population, with the most significant factors being a constant population size, the number of generations since founding, and the pathogenic loci and their allele frequencies among founders. Here we employed a cross-isolate genome-wide multipoint linkage study design using uniform genetic and clinical methods in four Daghestan ethnically and demographically diverse isolates with an aggregation of schizophrenia. Our previous population-genetics study showed that Daghestan has an extremely high genetic diversity between ethnic populations and a low genetic diversity within them. The isolates selected for this study include some with more than 200 and some with fewer than 100 generations of demographical history since their founding. Updated clinical data using DSM-IV criteria showed between-isolate differences in aggregation of distinct types of schizophrenia: one of the isolates had a predominant aggregation of disorganized schizophrenia, while the other three had predominantly paranoid schizophrenia. The summarized cross-isolate results indicated prominent within and between-isolate differences in clinical and genetic heterogeneity: the most ancient isolates have roughly twofold fewer incidences of distinct clinical phenotypes and fewer linked genomic regions compared to the demographically younger isolates, which exhibit higher clinical and genetic heterogeneity. Affected individuals in the demographically ancient isolate of ethnic Dargins (No. 6022) who suffered from disorganized schizophrenia showed the highest linkage evidence at 17p11-p12 (LOD=3.73), while isolates with a predominant aggregation of paranoid schizophrenia (Nos. 6005, 6011, and 6034) showed the highest linkage evidence at 22q11 (LOD=3.0 and 4.4). The unified clinical, genomic, and statistical design we used enabled us to separate the linked and unlinked pedigrees in an unbiased fashion for each genomic location. Overall maximized heterogeneity lod scores for the combined pedigrees ranging from 3.5 to 8.7 were found at 2p24, 10q26, 11q23, 12q24, 17p11-p12, 22q11, and 22q13. The cross-isolate homogeneity in linkage patterns may be ascribed to an identical-by-descent "metahaplotype" block with pathogenic loci derived from the Daghestan ethnic groups' common ancestral metapopulation, while the cross-isolate differences may reflect differences in gene drift and recombination events in the history of local isolates. The results obtained support the notion that mapping genes of any complex disease (e.g., schizophrenia) in demographically older genetic isolates may be more time and cost effective in comparison with demographically younger isolates, especially in genetically heterogeneous outbred populations, due to higher clinical and genetic homogeneity of the primary isolates. A study at higher genotyping density across the regions of interest and fluorescence in situ hybridization analyses are currently underway.

Chromosome Mapping↗

Hypothalamic abnormalities in schizophrenia: sex effects and genetic vulnerability.

BACKGROUND: This is a unique hypothalamic magnetic resonance imaging (MRI) study in schizophrenia, an important region in the limbic system. We hypothesized abnormal volumetric increases, with greater severity in multiplex families (more than one ill member) compared with simplex families (one ill). We tested the hypothesis that normal hypothalamic sexual dimorphism is disrupted in schizophrenia. METHODS: Eighty-eight DSM-III-R schizophrenia cases (40 simplex and 48 multiplex), 43 first-degree nonpsychotic relatives, and 48 normal comparisons systematically were compared. A 1.5-Tesla General Electric scanner was used to acquire structural MRI scans, and contiguous 3.1-mm slices were used to segment anterior and posterior hypothalamus. General linear model for correlated data and generalized estimating equations were used to compare cases, relatives, and controls on right and left hypothalamus, controlled for age, sex, and total cerebral volume. Spearman's correlations of hypothalamic volumes with anxiety were calculated to begin to examine arousal correlates with structural abnormalities. RESULTS: Findings demonstrated significantly increased hypothalamic volume in cases and nonpsychotic relatives, particularly in regions of paraventricular and mammillary body nuclei, respectively. This increase was linear from simplex to multiplex cases, was positively correlated with anxiety, and had a greater propensity in women. CONCLUSIONS: Findings suggest important implications for understanding genetic vulnerability of schizophrenia and the high rate of endocrine abnormalities.

Adult↗

The Consortium on the Genetics of Endophenotypes in Schizophrenia: model recruitment, assessment, and endophenotyping methods for a multisite collaboration.

BACKGROUND: The Consortium on the Genetics of Schizophrenia (COGS) is an ongoing, National Institute of Mental Health-funded, 7-site collaboration investigating the occurrence and genetic architecture of quantitative endophenotypes related to schizophrenia. The purpose of this article is to provide a description of the COGS structure and methods, including participant recruitment and assessment. METHODS: The hypothesis-driven recruitment strategy ascertains families that include a proband with a Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition diagnosis of schizophrenia, and at least one unaffected full sibling available for genotyping and endophenotyping, along with parents available for genotyping and (optional depending on age) endophenotyping. The family structure is selected to provide contrast in quantitative endophenotypic traits and thus to maximize the power of the planned genetic analyses. Probands are recruited from many sources including clinician referrals, local National Alliance for the Mentally Ill chapters, and advertising via the media. All participants undergo a standardized protocol that includes clinical characterization, a blood draw for genotyping, and endophenotype assessments (P50 suppression, prepulse inhibition, antisaccade performance, continuous performance tasks, letter-number span, verbal memory, and a computerized neurocognitive battery). Investigators participate in weekly teleconferences to coordinate and evaluate recruitment, clinical assessment, endophenotyping, and continuous quality control of data gathering and analyses. Data integrity is maintained through use of a highly quality-assured, centralized web-based database. RESULTS: As of February 2006, 355 families have been enrolled and 688 participants have been endophenotyped, including schizophrenia probands (n = 154, M:F = 110:44), first-degree biological relatives (n = 343, M:F = 151:192), and community comparison subjects (n = 191, M:F = 81:110). DISCUSSION: Successful multisite genetics collaborations must institute standardized methodological criteria for assessment and recruitment that are clearly defined, well communicated, and uniformly applied. In parallel, studies utilizing endophenotypes require strict adherence to criteria for cross-site data acquisition, equipment calibration and testing and software equivalence, and continuous quality assurance for many measures obtained across sites. This report describes methods and presents the structure of the COGS as a model of multisite endophenotype genetic studies. It also provides demographic information after the first 2 years of data collection on a sample for whom the behavioral data and genetics of endophenotype performance will be fully characterized in future articles. Some issues discussed in the reviews that follow reflect the challenges of evaluating endophenotypes in studies of the genetic architecture of endophenotypes in schizophrenia.

Cooperative Behavior↗

Successful multi-site measurement of antisaccade performance deficits in schizophrenia.

The antisaccade task is a promising schizophrenia endophenotype; it is stable over time and reflects neurophysiological deficits present in both schizophrenia subjects and their first-degree relatives. Meaningful genetic research requires large sample sizes that are best ascertained using multi-site study designs. To establish the criterion validity of the antisaccade task in a multi-site design, the Consortium on the Genetics of Schizophrenia (COGS) examined whether seven sites could detect previously reported antisaccade deficits in schizophrenia subjects. Investigators presented 3 blocks of 20 antisaccade stimuli to 143 schizophrenia subjects and 195 comparison subjects. Frequent collaborator communication, standardized training, and ongoing quality assurance optimized testing uniformity. Data were discarded from only 1.2% of subjects due to poor quality, reflecting the high fidelity of data collection and scoring methods. All sites detected a significant difference in the proportion of correct antisaccades between schizophrenia and comparison subjects (p<.02 at all sites); group differences in gain and latency were less robust. Regression analyses to adjust for the effects of group, site, age, gender, smoking, and parental education on the proportion of correct antisaccades revealed a significant effect of group, site, and age but no effect of gender, smoking, or parental education, and no group-by-site interactions. Intraclass correlations between proportion of correct antisaccades across the blocks of stimuli ranged from 0.87 to 0.93, demonstrating good within-session reliability at sites. These results confirm previous findings of antisaccade deficits in schizophrenia subjects and support the use of the antisaccade task as a potential schizophrenia endophenotype in multi-site genetic studies.

Adolescent↗

Hypomethylation of MB-COMT promoter is a major risk factor for schizophrenia and bipolar disorder.

The variability in phenotypic presentations and the lack of consistency of genetic associations in mental illnesses remain a major challenge in molecular psychiatry. Recently, it has become increasingly clear that altered promoter DNA methylation could play a critical role in mediating differential regulation of genes and in facilitating short-term adaptation in response to the environment. Here, we report the investigation of the differential activity of membrane-bound catechol-O-methyltransferase (MB-COMT) due to altered promoter methylation and the nature of the contribution of COMT Val158Met polymorphism as risk factors for schizophrenia and bipolar disorder by analyzing 115 post-mortem brain samples from the frontal lobe. These studies are the first to reveal that the MB-COMT promoter DNA is frequently hypomethylated in schizophrenia and bipolar disorder patients, compared with the controls (methylation rate: 26 and 29 versus 60%; P=0.004 and 0.008, respectively), particularly in the left frontal lobes (methylation rate: 29 and 30 versus 81%; P=0.003 and 0.002, respectively). Quantitative gene-expression analyses showed a corresponding increase in transcript levels of MB-COMT in schizophrenia and bipolar disorder patients compared with the controls (P=0.02) with an accompanying inverse correlation between MB-COMT and DRD1 expression. Furthermore, there was a tendency for the enrichment of the Val allele of the COMT Val158Met polymorphism with MB-COMT hypomethylation in the patients. These findings suggest that MB-COMT over-expression due to promoter hypomethylation and/or hyperactive allele of COMT may increase dopamine degradation in the frontal lobe providing a molecular basis for the shared symptoms of schizophrenia and bipolar disorder.

Alcoholism↗

Genome-wide linkage analysis of heroin dependence in Han Chinese: results from wave one of a multi-stage study.

The contribution of genes to the etiology of heroin dependence is greater than for any other illicit drug. The specific genes mediating this effect remain unknown, despite several candidate gene association studies of the condition. Here we report the results of a genome-wide search for heroin dependence susceptibility loci using multipoint linkage analysis. In phase I, we ascertained 207 independent affected sibling pairs from 202 Han Chinese families from Yunnan Province, China (near Asia's "Golden Triangle"). After data-cleaning, 194 fully independent sibling pairs (i.e., with no overlapping individuals) from 192 families were genotyped on 404 short tandem-repeat markers spaced at an average inter-marker distance of 9 cM. Although none of our findings achieved genome-wide significance, we found two regions with non-parametric linkage (NPL) Z-scores greater than 2.0. An NPL Z-score of 2.19 (uncorrected P-value = 0.014) was observed at D4S1644, located at 143.3 cM on chromosomal region 4q31.21. The highest NPL Z-score of 2.36 (uncorrected P-value = 0.009) was observed at 53.4 cM on chromosomal region 17q11.2 at marker D17S1880. This is among the first published reports of a genome-wide linkage analysis of heroin dependence. Forthcoming results from other groups and from two additional waves of ascertainment (one planned, one currently ongoing) for our own study should be able to support or refute the putative susceptibility loci we have identified, after which positional candidate genes can be further evaluated as risk factors for the illness.

China↗

No association of G72 and D-amino acid oxidase genes with schizophrenia.

The genes of D-amino acid oxidase (DAAO) activator (DAOA or G72; 13q34) and DAAO (12q24) have been suggested as candidate genes and involved in the N-methyl-D-aspartate receptor regulation pathway for schizophrenia. In order to evaluate the potential association of these two genes with schizophrenia in a Taiwanese sample, three single nucleotide polymorphisms (SNPs) for DAAO (rs2111902, rs3918346, rs3741775) and eleven SNPs for G72 (rs3916965, rs3916966, rs3916967, rs2391191, rs3916968, rs947267, rs778294, rs3916970, rs3916971, rs778293, rs3918342) were genotyped by the MALDI-TOF mass spectrometry method in 218 families (864 individuals) containing at least two siblings affected with schizophrenia. In SNP-based single locus association analyses, neither G72 nor DAAO showed significant association with schizophrenia. Additionally, a three-SNP haplotype in DAAO, and a four-SNP as well as a two-SNP haplotype in G72, showed no significant associations with schizophrenia. These results suggest that the DAAO and G72 genes are not susceptibility genes for schizophrenia in a Taiwanese sample.

Carrier Proteins↗

Evaluation of RGS4 as a candidate gene for schizophrenia.

Several studies have suggested that the regulator of G-protein signaling 4 (RGS4) may be a positional and functional candidate gene for schizophrenia. Three single nucleotide polymorphisms (SNP) located at the promoter region (SNP4 and SNP7) and the intron 1 (SNP18) of RGS4 have been verified in different ethnic groups. Positive results have been reported in these SNPs with different numbers of SNP combinatory haplotypes. In this study, these three SNP markers were genotyped in 218 schizophrenia pedigrees of Taiwan (864 individuals) for association analysis. Among these three SNPs, neither SNP4, SNP7, SNP18 has shown significant association with schizophrenia in single locus association analysis, nor any compositions of the three SNP haplotypes has shown significantly associations with the DSM-IV diagnosed schizophrenia. Our results fail to support the RGS4 as a candidate gene for schizophrenia when evaluated from these three SNP markers.

Alleles↗

Neuropsychological functioning in adolescents and young adults at genetic risk for schizophrenia and affective psychoses: results from the Harvard and Hillside Adolescent High Risk Studies.

Siblings and offspring of persons with schizophrenia carry elevated genetic risk for the illness and manifest attentional and memory impairments. Because less is known about other neuropsychological functions and their specificity in adolescents, we conducted a genetic high-risk (HR) study of schizophrenia (HR-SCZ) and affective psychosis (HR-AFF). Participants (ages 12-25) were from the Harvard Adolescent High-Risk and Hillside Family studies, including 73 HR-SCZ, 18 HR-AFF, and 84 community controls (CCs) recruited in metropolitan Boston and New York. Groups were compared on overall neurocognitive functioning, 6 domains, and 13 test scores, controlling for age, parental education, and correlated data within families. The HR-SCZ group was significantly impaired overall, while the HR-AFF group demonstrated a trend toward overall impairment. HR-SCZ subjects showed significantly lower Verbal Ability (d = .73) and Executive Functioning/Working Memory (d = .47) than CCs. HR-AFF subjects showed reduced Verbal Ability (d = .64) compared to CCs. Excluding 12 CCs with a parental history of depression (without psychosis) led to larger differences between HR and CC groups across domains. Moreover, HR-SCZ and CC group differences in Verbal Memory (d = .39) and Visual-Spatial (d = .34) became statistically significant. There were no significant differences between HR-SCZ and HR-AFF groups. Data support a modest neuropsychological deficit in persons at genetic HR for psychosis, with a broader range of deficits in HR-SCZ. Future work should assess the relationship of neurocognition to adaptive functioning and possible onset of psychosis in HR samples. Ascertainment criteria for controls may markedly influence results and interpretation of group differences.

Adolescent↗

Is there heterogeneity among syndromes of substance use disorder for illicit drugs?

The use of DSM criteria to evaluate liability to substance use disorders (SUDs) and to identify SUD phenotypes may not provide the sensitivity required to identify genes associated with vulnerability to SUDs. The purpose of this study is to evaluate a number of basic aspects of substance use that may be more proximal than full SUDs to risk genes, some of which may thus have greater potential utility as phenotypes in subsequent molecular genetic analyses. In this paper we present results from the first stage of our planned analyses, focusing on how individual symptoms of abuse and dependence may be used to create alternate phenotypes for SUDs. Specifically, we used factor analysis and biometrical modeling on each symptom of illicit substance abuse and dependence within different types of substances, and compared and contrasted factor patterns and heritabilities across the different substances. These analyses were carried out using a population-based sample of 3372 male-male twin pairs from the Vietnam Era Twin Registry who participated in the Harvard Twin Study of Substance Abuse. We obtained extensive data from these participants on substance use and SUDs via telephone interview in 1992, including data on the illicit substances: opiates, cocaine, cannabis, sedatives, stimulants, and psychedelics. The results indicate that: A) although a one-factor model assuming a single underlying liability for abuse and dependence symptoms and behaviors can be rejected for most substances, there is no uniform support for a two-factor model differentiating between abuse versus dependence; B) patterns of symptoms or behaviors reported by substance users vary across substances; C) not all symptoms or behaviors contribute equally to the presentation of an SUD; and D) the heritability of symptoms or behaviors of substance users varies both within and between substances. These results represent important first steps in facilitating the search for SUD-risk genes in subsequent high-throughput molecular genetic analyses by providing alternate phenotypes that may have both optimal validity and increased heritability.

Adult↗

Altered brain activation in dorsolateral prefrontal cortex in adolescents and young adults at genetic risk for schizophrenia: an fMRI study of working memory.

OBJECTIVE: Adult first-degree relatives of persons with schizophrenia carry elevated genetic risk for the illness, demonstrate working memory (WM) impairments, and manifest alterations in dorsolateral prefrontal cortical (DLPFC) function during WM. Because substantially less is known about these phenotypes in adolescent subjects we sought to demonstrate that young relatives of persons with schizophrenia manifest impaired WM and altered prefrontal activation. METHODS: Participants were 21 non-psychotic, unmedicated first-degree relatives of persons with a DSM-IV diagnosis of schizophrenia or schizoaffective disorder, depressed type and 24 unmedicated controls, recruited from the community and hospitals in metropolitan Boston (ages 13-28). We compared groups on an auditory WM task with interference prior to scanning and used functional magnetic resonance imaging (fMRI) to compare groups while performing visual 2-back WM and control vigilance tasks. Blood oxygen level dependent signal change was measured using two whole-brain gradient echo EPI pulse acquisitions (21 contiguous, 5mm axial slices), acquired on a Siemens 1.5T MR scanner. Data were analyzed using Statistical Parametric Mapping-99. RESULTS: The high risk subjects were significantly impaired on the auditory WM task, had significantly greater Phobic Anxiety, and marginally greater Psychoticism than controls on the Symptom Checklist-90-Revised, and showed significantly greater task-elicited activation in the right DLPFC (BA 46). Psychopathology, IQ, and in-scanner WM performance did not account for group differences in brain activation. CONCLUSIONS: Data support a physiological difference (an exaggerated fMRI response) in DLPFC in adolescents at genetic risk for schizophrenia, independent of psychosis. Future work can study the relationship of these measures to possible onset of schizophrenia.

Adolescent↗

Decreased volume of left and total anterior insular lobule in schizophrenia.

The insula is anatomically situated to be critically involved in many bio-behavioral functions impaired in schizophrenia. Furthermore, its total volume has been shown to be reduced in schizophrenia. In the present study, we tested the hypothesis that in schizophrenia it is the anterior insular lobule (aINS(lbl)) rather than the posterior insular lobule (pINS(lbl)) that is smaller, given that limbic system abnormalities are central in schizophrenia and that the affiliations of the limbic system are principally with the anterior insular lobule. We used T1-weighted high resolution magnetic resonance imaging (MRI) to measure the cortical volume of the left and right anterior and posterior insular subdivisions. The subjects included a sample of healthy community controls (N=40) and chronic patients with DSM-III-R schizophrenia (N=41). We correlated insula volumes with positive and negative symptoms. We found that the total aINS(lbl), and the left aINS(lbl) in particular, were significantly volumetrically smaller in schizophrenia compared to controls, and significantly correlated with bizarre behavior. Given that the anterior insular lobule offers anatomic features that allow for MRI-based morphometric analysis, namely its central and circular sulci, this brain structure provides a useful model to test hypotheses regarding genotype-phenotype relationships in schizophrenia using the anterior insular lobule as a candidate endophenotype.

Adolescent↗

Binge-eating disorder as a distinct familial phenotype in obese individuals.

CONTEXT: Binge-eating disorder (BED)-a syndrome that only recently has attracted scientific attention-is often seen in obese individuals, especially those with severe obesity. However, it remains unclear whether BED represents an etiologically distinct behavioral phenotype of obesity or simply a nonspecific eating pattern sometimes seen in obese individuals. OBJECTIVE: To test whether BED aggregates in families independently of obesity, and if so, whether familial factors for BED also independently increase the risk of obesity. DESIGN, PATIENTS, AND SETTING: Blinded family interview study of overweight or obese probands with (n = 150) and without (n = 150) BED, and their first-degree relatives (n = 888) in a community setting evaluated between October 2002 and July 2004. MAIN OUTCOME MEASURES: Lifetime diagnosis of BED; current and highest lifetime body mass index (calculated as the weight in kilograms divided by the square of the height in meters). RESULTS: Binge-eating disorder aggregated strongly in families independently of obesity (odds ratio, 2.2; 95% confidence interval, 1.4-3.6; P<.001). Furthermore, relatives of probands with BED displayed a markedly higher prevalence of severe obesity in adulthood (body mass index >/=40) than relatives of probands without BED even when controlling for proband body mass index (odds ratio, 2.5; 95% confidence interval, 1.4-4.4; P = .002). CONCLUSIONS: Binge-eating disorder is a familial disorder caused in part by factors distinct from other familial factors for obesity. Furthermore, these BED-specific familial factors may independently increase the risk of obesity, especially severe obesity. It follows that targeted interventions capable of preventing or treating traits influenced by these BED-specific familial factors could reduce the public health burden of obesity.

Adolescent↗

A discordant twin study of premorbid cognitive ability in schizophrenia.

Twin studies are advantageous because sources of genetic and environmental variation are equated in ways that are not possible in standard case-control designs. We examined premorbid cognitive ability by comparing Armed Forces Qualification Test scores administered at the time of military enlistment in 21 schizophrenia-discordant twin pairs and 860 matched control twins. Scores were significantly lower in schizophrenia probands than in their nonpsychotic co-twins; co-twins were midway between probands and control twins. Effects were reduced when the discordant pairs were extended to include 33 psychosis-discordant pairs. Compared with controls, education at enlistment was significantly lower in psychosis probands and in co-twins from both schizophrenia- and psychosis-disordant pairs. Co-twins from psychosis-discordant pairs had significantly lower education at midlife than controls. Results suggest that cognitive ability is influenced by familial vulnerability for schizophrenia or psychosis, and that premorbid cognitive ability is lower in schizophrenia versus psychosis in general. Educational advancement may be slightly slowed by this familial vulnerability, but results were equivocal with regard to attenuation of one's ultimate educational attainment.

Adult↗