• Dr. Glatt and Colleagues Reply

      Glatt, Stephen J.; Faraone, Stephen V.; Tsuang, Ming T. (American Psychiatric Association Publishing, 2004-06)
    • DRAMS: A tool to detect and re-align mixed-up samples for integrative studies of multi-omics data

      Jiang, Yi; Giase, Gina; Grennan, Kay; Shieh, Annie W.; Xia, Yan; Han, Lide; Wang, Quan; Wei, Qiang; Chen, Rui; Liu, Sihan; et al. (Public Library of Science (PLoS), 2020-04-13)
    • A dual to the death: using novel host-directed antivirals to promote death of HCMV-infected myeloid cells through apoptosis and necroptosis

      Chan, Gary; Cheung, Jennifer (2022-06)
      Human cytomegalovirus (HCMV) is a ubiquitous member of the betaherpesvirus family, with seroprevalence rates ranging from 40-100% worldwide. Although primary infection is asymptomatic in most immunocompetent patients, HCMV is a significant cause of morbidity and mortality in the immunosuppressed and immunonaїve, including transplant recipients, patients with AIDS, and developing fetuses in utero. The diverse clinical presentations of HCMV are attributable to the pervasive systemic dissemination and extensive cellular tropism of the virus. Peripheral blood monocytes are believed to be the key cells responsible for HCMV dissemination from the initial site of infection to distant organ systems. Monocytes are normally short-lived, surviving for only 48 h in circulation before undergoing apoptosis. Previous work from our lab has shown that HCMV circumvents the short lifespan of monocytes by inducing a noncanonical activation of Akt to upregulate the expression of antiapoptotic proteins, thereby prolonging survival of infected monocytes. HCMV promotes survival in the absence of viral replication and lytic gene expression, rendering current direct-acting antivirals ineffective against quiescently infected monocytes. There are currently no antivirals that target quiescent or latent HCMV infection. We hypothesize that targeting host proteins that are essential for HCMV's induction of monocyte survival mechanisms will reduce viability of infected monocytes, ultimately reducing systemic viral dissemination. The studies in this thesis investigate novel host-directed antivirals targeted at two different cellular factors and their efficacy against quiescent HCMV infection in monocytes. The first host protein under scrutiny as an antiviral target is Sirtuin 2 (Sirt2), an NAD+-dependent deacetylase. Treatment with novel Sirt2 inhibitors promoted death of HCMV-infected monocytes as a cellular antiviral defense response through two concurrent regulated death pathways: apoptosis and necroptosis. HCMV has developed mechanisms to impede both death pathways, but inhibition of Sirt2 relieves the viral obstructions on both pathways by disrupting HCMV's unique phosphorylation on Akt. The second host protein targeted as a potential antiviral strategy is Mcl-1, an antiapoptotic member of the Bcl-2 family of proteins. HCMV-infected monocytes are dependent on Akt-dependent upregulation of Mcl-1 for survival during early infection. Treatment with Mcl-1 inhibitors blocked interaction between Mcl-1 and proapoptotic protein Bak, reducing viability of infected monocytes. Subsequent testing of Mcl-1 inhibitors in an ex vivo skin organ culture system resulted in a decrease in HCMV-infected cells that crawled out of the skin tissue, suggesting that Mcl-1 inhibition may reduce viral dissemination. Our studies lay down the groundwork for the investigation of novel host-directed antivirals, an approach that successfully targets quiescent HCMV infection in peripheral blood monocytes for the first time. Expanding the study of host-directed antivirals may bring the field one step closer to the possibility of a comprehensive antiviral regimen that is effective against all stages of viral infection.
    • Effectiveness and Tolerability of Tomoxetine in Adults With Attention Deficit Hyperactivity Disorder

      Spencer, Thomas; Biederman, Joseph; Wilens, Timothy; Prince, Jeffry; Hatch, Mary; Jones, Janice; Harding, Margaret; Faraone, Stephen V.; Seidman, Larry (American Psychiatric Association Publishing, 1998-05)
      Objective: The authors assessed the experimental noradrenergic compound tomoxetine as an alternative treatment for adult attention deficit hyperactivity disorder (ADHD). Method: They conducted a double-blind, placebo-controlled, crossover study of tomoxetine in 22 adults with well-characterized ADHD. Results: Treatment with tomoxetine at an average oral dose of 76 mg/day was well tolerated. Drug-specific improvement in ADHD symptoms was highly significant overall and sufficiently robust to be detectable in a parallel-groups comparison restricted to the first 3 weeks of the protocol. Eleven of 21 patients showed improvement after receiving tomoxetine, compared with only two of 21 patients who improved after receiving placebo. Significant tomoxetine-associated improvement was noted on neuropsychological measures of inhibitory capacity from Stroop tests. Conclusions: This preliminary study showed that tomoxetine was effective in treating adult ADHD and was well tolerated. These promising results provide support for further studies of tomoxetine over an extended period of treatment.
    • EFFECTS OF FOCAL SEGMENTAL GLOMERULOSCLEROSIS-ASSOCIATED MUTATIONS ON MYOSIN 1E LOCALIZATION AND ACTIVITY

      Krendel, Mira; Karchin, Jing Bi (2015)
      Our lab has discovered that an actin-dependent molecular motor called Myosin 1e (Myo1e) is required for maintaining normal morphology and function in vivo of podocytes, a specialized epithelial cell in the kidney. We have found that Myo1e-null mice develop proteinuria, and mutations in the MYO1E gene, including missense mutations A159P and T119I, and nonsense mutation Y695X, have been identified in focal segmental glomerulosclerosis (FSGS), a primary kidney disease that often leads to end stage renal disease (ESRD). Based on these findings, we have proposed that Myo1e and especially its motor domain, plays a key role in regulating actin cytoskeleton organization in kidney podocytes. To study Myo1e activity at the junctions, we have used cell culture systems. We confirmed that Myo1e is a component of the podocyte slit diaphragm using glomerular fractionation assay and immune-gold labeling electron microscopy. Disruption of Myo1e motor activity by point mutation (A159P) completely disrupted Myo1e cellular localization and led to defective actin assembly at nascent cell-cell contacts. Domain mapping experiments in MDCK cells have suggested that the Myo1e TH2 domain is necessary, but not sufficient for its localization, but addition of the TH1 domain restores its localization to junctions. We have also found that the Myo1e SH3 domain interacts with ZO-1, a slit diaphragm and tight junction protein, in invitro pulldown assays, which might contribute to ZO-1 exchange activity at the junctions. Another FSGS-associated Myo1e motor domain mutation (T119I) also caused mis-localization of Myo1e in the cultured mouse podocytes, suggesting loss-of-function of the motor domain mutants. We have also shown that ZO-1 is not recruited to the nascent cell-cell contacts at the same time with the Myo1e T119I mutants. Finally, by using fission yeast as a model system, we have demonstrated that human kidney disease-associated mutations in fission yeast caused defects in yeast growth and endocytosis processes. Interestingly, after analyzing the colocalization patterns between the FSGS-associated Myo1 mutants and Chaperone Rng3, we have proposed that these two kidney disease-associated mutants likely possess different disease-causing mechanisms.Above all, we have concluded that Myo1e motor domain plays an important role in its localization and activity in podocyte actin cytoskeleton, which might be the link to the disease mechanism of FSGS at the molecular level.
    • Effects of Rab4A Mutations on Mouse Behavior, mTORC1 Activity,and Surface 8Receptor/TransporterRecycling

      Perl, Andras; Winans, Thomas C (2020-10-03)
      Through studying endosomal regulation, I found that a single amino acid 47mutation (Q72L) in the Rab4A gene leads to neurological disorders in two separate 48mouse strains. In the C57Bl/6 (SLE(WT)) background,I found thatknock-in the 49Rab4A gene leads to hyperactivity, which resembles both autism spectrum 50disorders (ASD) and attention-deficit hyperactivity disorder (ADHD). On a lupus-51prone background (SLE(1.2.3)) I found thatthe same mutation led to hypoactivity, 52which indicates a more severe neuropsychiatric systemic lupus erythematosus 53(NPSLE) than SLE(1.2.3)mice with wild type Rab4A.54The same mice were studied in chapter two, where mTORC1 activity was 55confirmed to be elevated in CD4+ T cells when Rab4A was knocked-in (Rab4A(KI))56compared to Rab4A(WT) cells.In young mouse brains prior to disease onset, I found57increases of mTORC1 and oxidative stress in Rab4A(KI) brains relative to 58Rab4A(WT) brains. In the same brains, there was also a depletion of GLUT1 and 59IFNGR1.Many of these changes were absent in the adult mice, after disease had 60developed.61SLE(1.2.3) mice with the three Rab4A alleleswere treated withrapamycin or 62NAC,and brains were collected.In these brains, there wasevidence that the 63hypoactive Rab4A(KI) SLE(1.2.3) had lower mTORC1 activity than Rab4A(WT) and 64Rab4A(KO) mice.This finding indicatesdepression, which is a pattern seen in major 65depressive disorder(MDD). Depression is also a symptoms of NPSLE. Interestingly, 66rapamycin increased mTORC1 activity in theRab4A(KI)brains compared Rab4A(KI) 67mice treated with vehicle, indicating a positive effect from the drug.
    • THE EFFECTS OF VARYING ACTIN AND CAPPING PROTEIN CONCENTRATIONS ON ACTIN PATCH DYNAMICS IN FISSION YEAST

      Sirotkin; Plante, Kyle (2015)
      Actin assembly into structures called endocytic actin patches is directly responsible for driving endocytic invagination and internalization. We tested the predictions made from the mathematical modeling of the Dendritic Nucleation Model of actin assembly at sites of clathrin-mediated endocytosis in fission yeast (Berro et al.; Sirotkin et al., 2010). The model predicts that increasing the concentration of cytoplasmic actin or deleting capping protein will cause an increase in the extent and the rate of actin assembly in actin patches. Conversely, the model predicts that increasing the concentration of capping protein or decreasing the actin concentration will cause a decrease in the extent and the rate of actin assembly in actin patches. To test these predictions, we used the actin cross-linking protein, fimbrin Fim1 tagged with a fluorescent protein to measure actin patch dynamics in strains that over- or under-express actin, over-express capping protein, or have deletions of the two capping protein genes. In contrast to model predictions, we found that manipulating capping protein concentrations did not have a significant effect on the extent of actin patch assembly and affected the rates of assembly to a lesser degree than expected from the model, suggesting that capping protein is not the only factor that limits actin patch assembly. Surprisingly, changes in the concentration of actin resulted in changes in the number of patches in a cell, suggesting that the concentration of actin is more important in controlling the initiation of new patches rather than in patch assembly. Through studying the biochemical pathway of actin assembly directly in living cells, we were able to gain insights into previously under-appreciated aspects of the mechanism of actin assembly at the sites of clathrin-mediated endocytosis.
    • Environmental risk factors for attention‐deficit hyperactivity disorder

      Banerjee, Tania Das; Middleton, Frank; Faraone, Stephen V. (Wiley, 2007-06-15)
      Attention-deficit hyperactivity disorder (ADHD) is the most common cognitive and behavioural disorder diagnosed among school children. It is characterized by deficient attention and problem solving, along with hyperactivity and difficulty withholding incorrect responses. This highly prevalent disorder is estimated to affect 5–10% of children and in many cases, persists into adulthood, leading to 4% prevalence among adults. Converging evidence from epidemiologic, neuropsychology, neuroimaging, genetic and treatment studies shows that ADHD is a valid medical disorder. The majority of studies performed to assess genetic risk factors in ADHD have supported a strong familial nature of this disorder. Family studies have identified a 2- to 8-fold increase in the risk for ADHD in parents and siblings of children with ADHD. Various twin and adoption studies have also highlighted the highly genetic nature of ADHD. In fact the mean heritability of ADHD was shown to be 0.77, which is comparable to other neuropsychiatric disorders such as schizophrenia or bipolar disorder. However, several biological and environmental factors have also been proposed as risk factors for ADHD, including food additives/diet, lead contamination, cigarette and alcohol exposure, maternal smoking during pregnancy, and low birth weight. Many recent studies have specifically examined the relationships between ADHD and these extraneous factors. This review describes some of these possible risk factors.
    • Ethanol-Induced Effects of the Microtranscriptome on Natural Gene Expression

      Middleton, Frank; Ignacio, Cherry Mae Gonzalez
      Reliable, minimally invasive biomarkers that predict the extent of alcoholism-induced CNS damage are currently lacking. This limits the selection of rational interventions and hampers the ability to gauge therapeutic effects. Developing biomarkers that indicate early CNS damage may prove useful in deterring the emergence of alcohol use disorders (AUDs). Extracellular microRNAs (miRNAs) can be informative molecular indicators of neuronal gene expression alterations. They repress large fractions of protein-coding genes and are highly-involved in intercellular signaling between both proximal and distal neurons. This work has focused on (1) examining whether extracellular miRNAs in the serum of individuals diagnosed with AUDs can be used as biomarkers of alcohol-induced brain damage, (2) determining in vivo the ethanol-inducedeffects imparted by miRNAs and their targets in the brain, (3) evaluating their role ininterventions that can reverse behavioral impairment and (4) testing the ability of extracellular miRNAs to transfer ethanol-induced pathologies to ethanol-naive cells. There are five major findings from this work. First, two independent quantification technologies demonstrated comparable differences in miRNA expression levels betweenAUDs and controls and revealed significant correlations between candidate miRNA biomarkers and medical, neuroimaging and drinking parameters. Second, in rats manymiRNAs significantly altered by ethanol in the hippocampus following maternal or postnatal exposure were also changed in the serum. Moreover, postnatal consumption activated cell-cycle pathways in the hippocampus while maternal exposure affected unfolded protein response pathways in adolescent offspring. Third, the lack of social motivation seen following fetal exposure was reversed as a result of social enrichment. Analysis of the integrated data in the amygdala and ventral striatum revealed several functional gene networks whose activation patterns following fetal ethanol exposure were reversed by social enrichment. Fourth, transfer of purified exosomes from ethanol-exposed to ethanol-naive cells conferred many gene expression changes consistent with ethanol exposure. Lastly, examination of all the data revealed consistent changes in miRNAs that independently converged on cell death, cell proliferation and cell cycle regulatory processes, regardless of the species, paradigm and source. The findings in this work illustrate the utility of miRNAs as peripheral biomarkers of AUDs and suggest novel epigenetic mechanisms affected by alcohol.
    • EVALUATION OF THE ROLE OF THE CENTRAL PAIR IN CHLAMYDOMONAS REINHARDTII FLAGELLAR MOTILITY

      Mitchell, David; Smith, Brandon (2013)
      Cilia and flagella are essential for the function of nearly all eukaryotes. This organelle is made up of nine outer doublet microtubules and two central singlet microtubules to form the canonical (9+2) ciliary structure. Cilia and flagella use this structure, as well as several protein complexes, such as the outer and inner dynein arms, the radial spokes, and the proteins that decorate the central pair to propagate the bending that produces motion. Flagellar motion is highly regulated, and each of these structures is necessary to regulate the dynein arms that generate the motile force. The central pair is one of the least understood of these structures. To date there are two major impediments hindering our understanding of the central pair: a lack of understanding as to how distinct central pair structures work in concert, and a general lack of available central pair mutant strains in the model organism Chlamydomonas reinhardtii. In order to further our understanding of how the central pair functions I have used multiple strategies. Firstly I have used previously characterized central pair mutants to study both structural interactions within the central pair and how the double mutant affects motility regulation. Secondly I provide evidence that a potential central pair mutant, H2, is indeed a central pair mutant and affects the C2b projection. Lastly I will attempt to characterize a new Chlamydomonas mutant, 10B5. Together these analyses will demonstrate that double mutants can have an additive effect on the structure of the central pair, and that double central pair mutants do not appear to suppress one another, but are at least ivepistatic to the most severe phenotype. I will also show evidence that 10B5 is not a central pair mutant, but with further study it may offer new insight into motilityregulation.
    • Evidence for Similar Structural Brain Anomalies in Youth and Adult Attention-Deficit/Hyperactivity Disorder: A Machine Learning Analysis

      Zhang-James, Yanli; Helminen, Emily C; Liu, Jinru; Franke, Barbara; Hoogman, Martine; Faraone, Stephen V. (Cold Spring Harbor Laboratory, 2019-02-11)
      Attention-deficit/hyperactivity disorder (ADHD) affects 5% of children world-wide. Of these, two-thirds continue to have impairing symptoms of ADHD into adulthood. Although a large literature implicates structural brain differences of the disorder, it is not clear if adults with ADHD have similar neuroanatomical differences as those seen in children with recent reports from the large ENIGMA-ADHD consortium finding structural differences for children but not for adults. This paper uses deep learning neural network classification models to determine if there are neuroanatomical changes in the brains of children with ADHD that are also observed for adult ADHD, and vice versa. We found that structural MRI data can significantly separate ADHD from control participants for both children and adults. Consistent with the prior reports from ENIGMA-ADHD, prediction performance and effect sizes were better for the child than the adult samples. The model trained on adult samples significantly predicted ADHD in the child sample, suggesting that our model learned anatomical features that are common to ADHD in childhood and adulthood. These results support the continuity of ADHD’s brain differences from childhood to adulthood. In addition, our work demonstrates a novel use of neural network classification models to test hypotheses about developmental continuity.
    • Evidence for the multigenic inheritance of schizophrenia

      Freedman, Robert; Leonard, Sherry; Olincy, Ann; Kaufmann, Charles A.; Malaspina, Dolores; Cloninger, C. Robert; Svrakic, Dragan; Faraone, Stephen V.; Tsuang, Ming T. (Wiley, 2002-08-21)
      Schizophrenia is assumed to have complex inheritance because of its high prevalence and sporadic familial transmission. Findings of linkage on different chromosomes in various studies corroborate this assumption. It is not known whether these ®endings represent heterogeneous inheritance, in which various ethnic groups inherit illness through different major gene effects, or multigenic inheritance, in which affected individuals inherit several common genetic abnormalities. This study therefore examined inheritance of schizophrenia at different genetic loci in a nationally collected European American and African American sample. Seventy-seven families were previously genotyped at 458 markers for the NIMH Schizophrenia Genetics Initiative. Initial genetic analysis tested a dominant model, with schizophrenia and schizoaffective disorder, depressed type, as the affected phenotype. The families showed one genome-wide significant linkage (Z ¼ 3.97) at chromosome 15q14, which maps within 1 cM of a previous linkage at the a7-nicotinic receptor gene. Chromosome 10p13 showed suggestive linkage (Z ¼ 2.40). Six others (6q21, 9q32, 13q32, 15q24, 17p12, 20q13) were positive, with few differences between the two ethnic groups. The probability of each family transmitting schizophrenia through two genes is greater than expected from the combination of the independent segregation of each gene. Two trait-locus linkage analysis supports a model in which genetic alleles associated with schizophrenia are relatively common in the general population and affected individuals inherit risk for illness through at least two different loci.
    • Examination of the effects of Myosin-1e expression on tumor behavior and computational analysis of MYO1E mutations associated with kidney disease

      Krendel, Mira; Plante, Eric (2022-08-19)
      Actin and actin cytoskeleton associated proteins are important for maintenance of cellular homeostasis and cellular processes such as cell polarization, cell movement, and endocytosis. The long-tailed class one myosin, Myosin-1e (Myo1e), is an actin dependent molecular motor that is found to be expressed in and contribute to the function of epithelial cells. Specific mutations of Myo1e are associated with dysfunction of specialized kidney epithelial cells known as podocytes and increased incidence of kidney disease. We found that disease associated mutation of Myo1e affects the conformation of key functional domains within the Myo1e protein structure using molecular dynamic simulations (Chapter 2). This finding leads to a more mechanistic understanding of dysfunctional Myo1e protein conformational pathways that may be associated with kidney disease. We also find that Myosin-1e expression influences the behavior of mammary tumors in mice (Chapter 3). Specifically, mammary epithelial cell oncogenic transformation induced using the MMTV-PyMT oncogene (mouse mammary tumor virus, polyoma middle T-antigen) was phenotypically altered in mice lacking Myo1e expression compared to Myo1e expressing mice. The tumor cells in mice lacking Myo1e were more differentiated and expressed transcriptomic profiles associated with tumor suppression compared to the more oncogenic profiles of Myo1e expressing cells. In-vitro analysis revealed a cell autonomous effect of Myo1e expression on cell-cell junctional strength and gene expression associated with differentiation (Chapter 3). Appendix chapters 1 and 2 discuss experiments examining Myo1e expression on in-vitro cell migration and epithelial to mesenchymal transition (EMT). Overall, experiments discussed in this thesis have uncovered insight into the effects of Myo1e expression on breast cancer progression, cell differentiation and motility. Moreover, experiments in this thesis also contribute to further understanding of the dynamics of protein conformation associated with disease mutations of a class one myosin.
    • Examining the Comorbidity Between Attention Deficit Hyperactivity Disorder and Bipolar I Disorder: A Meta-Analysis of Family Genetic Studies

      Faraone, Stephen V.; Biederman, Joseph; Wozniak, Janet (American Psychiatric Association Publishing, 2012-12)
      Objective: The existence of comorbidity between attention deficit hyperactivity disorder (ADHD) and bipolar I disorder has been documented in clinical and epidemiological studies, in studies of children and adults, and in diagnosed ADHD and bipolar I patient samples. Yet questions remain about the validity of diagnosing bipolar I disorder in ADHD youth. The authors aim to clarify these issues by reviewing family genetic studies of ADHD and bipolar I disorder. Method: The authors applied randomeffects meta-analysis to family genetic studies of ADHD and bipolar I disorder. Twenty bipolar proband studies provided 37 estimates of the prevalence of ADHD in 4,301 relatives of bipolar probands and 1,937 relatives of comparison probands. Seven ADHD proband studies provided 12 estimates of the prevalence of bipolar I disorder in 1,877 relatives of ADHD probands and 1,601 relatives of comparison probands. Results: These studies found a significantly higher prevalence of ADHD among relatives of bipolar probands and a significantly higher prevalence of bipolar I disorder among relatives of ADHD probands. These results could not be accounted for by publication biases, unusual results from any one observation, sample characteristics, or study design features. The authors found no evidence of heterogeneity in the ADHD or bipolar family studies. Conclusions: The results suggest that ADHD plus bipolar comorbidity cannot be accounted for by misdiagnoses, but additional research is needed to rule out artifactual sources of comorbidity. More research is also needed to determine whether comorbidity of ADHD and bipolar I disorder constitutes a familial subtype distinct from its constituent disorders, which if confirmed would have implications for diagnostic nosology and genetic studies.
    • Expression and Function of Paxillin Genes in Zebrafish: A Role in Skeletal Muscle Development

      Turner, Chris; Amack, Jeffrey; Jacob, Andrew (2017)
      Paxillin is a key component of the Integrin adhesion complex, which regulates cellular signaling events in response to extracellular matrix interactions. Although the roles for Paxillin in cell migration have been extensively studied, less is understood about its role in vertebrate development. Depletion of Paxillin from mouse embryos results in early lethality due to impaired cardiovascular development and function, necessitating the development of alternative vertebrate genetic models for examining the role of Paxillin during embryogenesis. Zebrafish have emerged as an experimental vertebrate model amenable to genetic manipulation. The work compiled herein first characterizes the expression profiles for Paxillin genes in zebrafish, and then describes the embryonic phenotypes observed upon mutation of these genes. The identification of two Paxillin genes in zebrafish, pxnaand pxnb, provided new insight into the evolution of this gene family in the Teleost lineage. Both overlapping and unique expression profiles for these genes during zebrafish embryogenesis were uncovered. While both genes are expressed in developing skeletal muscle, pxnawas restricted to the notochord during earlier stages of embryogenesis and pxnbwas expressed in the developing heart. Targeted mutation of either gene alone did not impair embryonic development, suggesting partial functional redundancy between each gene during embryogenesis. Accordingly, combined mutations in pxnaand pxnbrevealed defects during the development ofseveral embryonic tissues. In particular, skeletal muscle morphogenesis iiiwas perturbed in these double mutant embryos. Further characterization revealed that Paxillin genes in zebrafish serve to regulate embryonic myotome shape and proper extracellular matrix composition during muscle development. The amount of Laminin was reduced, while the abundance of Fibronectin persisted, during myotome morphogenesis in Paxillin double mutant embryos. In addition, a role for cytoskeletal contractility in regulatingsubcellular localization of Paxillin in developing skeletal muscle was established. Defects in the development of the cardiovascular system were also apparent in Paxillin double mutant embryos, and future work will focus on characterizing these in further detail. Altogether, this work provides a new vertebrate model to use for understanding the role of Paxillin during embryonic development, and uncovers an unrecognized role for Paxillin in establishing the extracellular matrix of skeletal muscle.
    • Familial Risk Analyses of Attention Deficit Hyperactivity Disorder and Substance Use Disorders

      Biederman, Joseph; Petty, Carter R.; Wilens, Timothy E.; Fraire, Maria G.; Purcell, Caitlin A.; Mick, Eric; Monuteaux, Michael C.; Faraone, Stephen V. (American Psychiatric Association Publishing, 2008-01)
      Objective: A robust and bidirectional comorbidity between attention deficit hyperactivity disorder (ADHD) and psychoactive substance use disorder (alcohol or drug abuse or dependence) has been consistently reported in the extant literature. Method: First-degree relatives from a large group of pediatrically and psychiatrically referred boys with (112 probands, 385 relatives) and without (105 probands, 358 relatives) ADHD were comprehensively assessed by blind raters with structured diagnostic interviews. Familial risk analysis examined the risks in first-degree relatives for ADHD, psychoactive substance use disorder, alcohol dependence, and drug dependence after stratifying probands by the presence and absence of these disorders. Results: ADHD in the proband was consistently associated with a significant risk for ADHD in relatives. Drug dependence in probands increased the risk for drug dependence in relatives irrespective of ADHD status, whereas alcohol dependence in relatives was predicted only by ADHD probands with comorbid alcohol dependence. In addition, ADHD in the proband predicted drug dependence in relatives, and drug dependence in comparison probands increased the risk for ADHD in relatives. Both alcohol dependence and drug dependence bred true in families without evidence for a common risk between these disorders. Conclusions: Patterns of familial risk analysis suggest that the association between ADHD and drug dependence is most consistent with the hypothesis of variable expressivity of a common risk between these disorders, whereas the association between ADHD and alcohol dependence is most consistent with the hypothesis of independent transmission of these disorders. Findings also suggest specificity for the transmission of alcohol and drug dependence.
    • Family based association analysis of statistically derived quantitative traits for drug use in ADHD and the dopamine transporter gene

      Lasky-Su, Jessica; Biederman, Joseph; Doyle, Alysa E.; Wilens, Timothy; Monuteaux, Michael; Smoller, Jordan W.; Faraone, Stephen V. (Elsevier BV, 2006-06)
      Objective To determine whether SNPs within the dopamine transporter gene (DAT) are associated with quantitative phenotypes generated from drug frequency variables in an ADHD sample. Method 35 SNPs were genotyped in and around DAT. We developed a quantitative phenotype at each SNP by weighting the drug frequency variables. The weights were selected to maximize the heritability at each SNP. Once a quantitative phenotype was generated at each SNP, a screening procedure was used to select and test the SNPs with the greatest power to detect an association in DAT. Results No SNPs in DAT were associated with the quantitative phenotypes generated from the drug frequency variables after the multiple comparisons adjustment; however, some SNPs achieved nominal significance. A sliding window of analysis of 3 SNPs also resulted in only nominal associations. Conclusions SNPs in DAT do not appear to be associated with the phenotypes generated from drug frequency variables among individuals with ADHD.
    • Family based association study of pediatric bipolar disorder and the dopamine transporter gene (SLC6A3)

      Mick, Eric; Kim, Jang Woo; Biederman, Joseph; Wozniak, Janet; Wilens, Timothy; Spencer, Thomas; Smoller, Jordan W.; Faraone, Stephen V. (Wiley, 2008-10-05)
      Thedopaminetransportergene(SLC6A3) isacompelling candidate for pediatric bipolar disorder because (a) it has been associated with ADHD, (b) bipolar comorbidity with ADHD has been hypothesized to be an etiologically distinct familial subtype (c) blockade of the dopamine transporter with psychostimulants can induce mania in susceptible individualsand(d) previous studies have implicated the gene in bipolar disorder in adults. We conducted a family-based association study of SLC6A3 in 170 affected offspring trios defined by a child (12.9 5.3 years of age)with DSM-IV Bipolar-I disorder. Twenty-eight tag SNPs were chosen from the CEU (European) population of the International HapMap project (www.hapmap.org). Results indicated nominally positive association for 4 SNPs (rs40184, rs11133767, rs3776512, and rs464049), but only rs40184 survived correction formultiple statistical comparisons (P¼0.038). This is the first examination of the association with SLC6A3 and bipolar disorder in children and, like previous findings in adults with bipolar disorder, we found evidence of association with SNPs in the 30 region of the gene. These data provide suggestive evidence supporting a role for SLC6A3 in the etiology of pediatric bipolar disorder.
    • Family-based and case-control association studies of catechol-O-methyltransferase in attention deficit hyperactivity disorder suggest genetic sexual dimorphism

      Qian, Qiujin; Wang, Yufeng; Zhou, Rulun; Li, Jun; Wang, Bing; Glatt, Stephen; Faraone, Stephen V. (Wiley, 2003-03-04)
      Attention deficit hyperactivity disorder (ADHD) is the most common childhood-onset behavioral disorder. Boys are more often affected than girls. Family, twin, and adoption studies have supported a strong genetic basis. Some studies show that a catechol-O-methyltransferase (COMT) polymorphism affecting enzyme activity was associated with personality characteristics and diseases, such as novelty-seeking personality, substance abuse, and heroin addiction, whose features are similar to ADHD or are associated with ADHD. These findings suggest that the COMT gene may be a candidate gene for ADHD. TDT, HHRR, and case-control association studies were conducted within a sample of 202 nuclear ADHD families, 340 ADHD cases, and 226 controls in the Han Chinese population. Diagnoses and ADHD subtypes were ascertained according to DSM-IV criteria using American Clinical Diagnostic Interviewing Scales. The HHRR analysis suggested that the low enzyme-activity COMT Met allele was preferentially transmitted to ADHD boys (160 trios, χ2 = 3.858, P = 0.05, df = 1) but not girls. This association is particularly pronounced among male ADHD probands without any comorbidity (50 trios, HHRR: χ2 = 5.128, P = 0.024, df = 1; TDT: χ2 = 4.558, P = 0.033, df = 1), especially the ADHD-I subtype (32 trios, HHRR: χ2 = 5.792, P = 0.016, df = 1; TDT: χ2 = 5.333, P = 0.021, df = 1). The case-control study revealed that the Val allele was more frequent in females meeting ICD-10 or DSM-IV criteria for ADHD than in female controls (86 and 79.5%, respectively, χ2 = 4.059, P = 0.044, df = 1). Although these results suggest the COMT gene exerts some influence on the risk for ADHD in the Han Chinese population, given the potential for Type I error, these findings require replication before drawing definitive conclusions. © 2003 Wiley-Liss, Inc.
    • Family-based association study of markers on chromosome 22 in schizophrenia using African-American, European-American, and Chinese families

      Takahashi, Sakae; Cui, Yu-hu; Kojima, Takuya; Han, Yong-hua; Zhou, Ru-lum; Kamioka, Masashi; Yu, Shun-ying; Matsuura, Masato; Matsushima, Eisuyke; Wilcox, Marsha; et al. (Wiley, 2003-06-13)
      Several studies suggest that loci at chromosome 22q11.2-q13 might be linked to susceptibility to schizophrenia. Here we performed family-based association studies on chromosome 22q using 12 DNA microsatellite markers in African-American, European-American, and Chinese pedigrees. The marker D22S683 showed significant linkage and association with schizophrenia in not only the European-American sample but also in a combined sample (European-American and Chinese samples). Notably, D22S683 is located nearby and between D22S278 and D22S283, which have shown linkage and association to schizophrenia in prior reports. However, we found no significant association for the African-American sample. In conclusion, our data provide further support for the idea that the region around D22S683 contains a susceptibility gene for schizophrenia. © 2003 Wiley-Liss, Inc.