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A Positional Cloning Study on Schizophrenia

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00155649
Recruitment Status : Completed
First Posted : September 12, 2005
Last Update Posted : December 20, 2005
Information provided by:
National Taiwan University Hospital

Brief Summary:

This Group of Genomic Research in Psychiatric Disorders (GENOP) located at the Department of Psychiatry, College of Medicine and National Taiwan University Hospital (NTUH) had completed a serial psychopathological study of schizophrenia (SCH) defined by DSM-IV criteria. The results of this GENOP included: (1) delineating 2 to 3 subtypes of schizophrenia with prospective follow-up validity; (2) finding a trait marker of impaired attention measured by continuous performance test (CPT); (3) impaired executive function assess by Wisconsin Card Sorting Test (WCST) and impaired inhibition of P50 evoked potential; (4) five dinucleotide repeat polymorphism (DRP) markers in 5 different chromosomes with significant linkage scores, including D1S251 at 1q42.1, D6S296 at 6p22 , D8S1222 at 8p14, and D15S976 at 15q14, and D22S278 at 22q12; (5) finding a significant linkage of polymorphism marker located in a neurodevelopmental gene NOTCH4 ( 6p22); and neurophysiological function related gene CHNRA7 (15q14); (6) successfully collected 700 multiplex families, collected by the collaboration between of NTUH, Taiwan - NIMH, USA in the Taiwan Schizophrenia Genetic Linkage Study (TSLS) project, with at least two siblings affected with schizophrenia in Taiwan. A genome-wide scan on this big sample will be completed recently in the laboratory of NIMH, U.S.A.. Around 300 families had also CPT data in the whole family. This is probably the biggest number of multiplex families of a single ethnicity all over the world; (7) successfully setting up DNA and cell banks as well as clinical data bank. This substantial long track of this GENOP provided convincing background for this Positional Cloning Study on Schizophrenia (POCOS).

Understanding the controversial results of current linkage study on SCH world-wide, this POCOS was designed to make a break through design in the study for locating and identifying the vulnerability genes of SCH by using (1) phenomenological subtypes; (2) endophenotype defined by impaired attention (CPT) and/or impaired executive function (WCST); (3) using large enough size of samples of a single ethnicity of Taiwanese family pedigrees.

Major research tasks include (1) Linkage analysis and quantitative trait loci analysis, in collaboration with the team of Harvard Medical School, on the endophenotype defined by impaired attention and impaired executive function in 300 families with at least two siblings affected with SCH; (2) Two stages of genotyping, using High Throughput technology, of dense SNP markers, around DRP markers with significant linkage scores in the NTUH and TSLS studies, with average marker interval of 30kb in 3000 subjects of 700 multiplex families (a total of 300 markers) for linkage and quantitative trait loci analysis; (3) Two stages of study on the polymorphisms and/or mutations of candidate genes using association study and TDT test. Each stage with 10 Candidate Genes in the NTUH and TSLS project, respectively. In the first stage, these are: (a) Neurodevelopmental related genes: DISC1, TRAX (1q42.1), NOTCH4 and TNF(6p21.3) and NT-3; (b) Neurotransmitter receptor genes of CHNRA7 (15q14) and NMDA related to attention impairment; (c) Neurotransmitter metabolizing enzyme gene COMT (22q11.2) related to impaired frontal lobe function; and (d) Pharmacology related genes of DRD3 and 5HTA2.

Condition or disease

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Study Type : Observational
Enrollment : 320 participants
Observational Model: Defined Population
Time Perspective: Other
Study Start Date : April 2002
Study Completion Date : April 2005

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Schizophrenia

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 65 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Clinical diagnosis of Schizophrenia
  • Two children and one parent in the same family all have the clinical diagnosis of schizophrenia

Exclusion Criteria:

  • One parent should be normal

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00155649

Sponsors and Collaborators
National Taiwan University Hospital
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Study Chair: Hai-Gwo Hwu, Professor National Taiwan University
Layout table for additonal information Identifier: NCT00155649    
Other Study ID Numbers: 33979
First Posted: September 12, 2005    Key Record Dates
Last Update Posted: December 20, 2005
Last Verified: October 2001
Keywords provided by National Taiwan University Hospital:
vulnerability gene
positional cloning
subtype definition
genetic marker
genetic linkage
candidate genes
Additional relevant MeSH terms:
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Schizophrenia Spectrum and Other Psychotic Disorders
Mental Disorders