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A Positional Cloning Study on Schizophrenia

This study has been completed.
ClinicalTrials.gov Identifier:
First Posted: September 12, 2005
Last Update Posted: December 20, 2005
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Information provided by:
National Taiwan University Hospital

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.


Study Type: Observational
Study Design: Observational Model: Defined Population
Primary Purpose: Screening
Time Perspective: Longitudinal
Time Perspective: Retrospective/Prospective

Resource links provided by NLM:

Further study details as provided by National Taiwan University Hospital:

Estimated Enrollment: 320
Study Start Date: April 2002
Estimated Study Completion Date: April 2005
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Ages Eligible for Study:   18 Years to 65 Years   (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
  Contacts and Locations
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 ClinicalTrials.gov identifier (NCT number): NCT00155649

Sponsors and Collaborators
National Taiwan University Hospital
Study Chair: Hai-Gwo Hwu, Professor National Taiwan University
  More Information

ClinicalTrials.gov Identifier: NCT00155649     History of Changes
Other Study ID Numbers: 33979
First Submitted: September 9, 2005
First Posted: September 12, 2005
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:
Schizophrenia Spectrum and Other Psychotic Disorders
Mental Disorders