Clinical trial NCT00562926: Single Nucleotide Polymorphism (SNP) in Schizophrenia and Schizophrenia Spectrum Disorders: a Population Association Analysis With Hong Kong Chinese
Official title: Single Nucleotide Polymorphism (SNP) in Schizophrenia and Schizophrenia Spectrum Disorders: a Population Association Analysis With Hong Kong Chinese
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Schizophrenia
Keywords: Schizophrenia
Schizophrenia spectrum disorder
Lead sponsor: Hospital Authority, Hong Kong
Sponsor class: OTHER_GOV
Collaborators: name: Chinese University of Hong Kong
First posted: 2007-11-26
Enrollment: 32
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Time perspective: PROSPECTIVE

Brief summary: Gamma-aminobutyric acid (GABA) is the principal inhibitory neurotransmitter in the mammalian central nervous system. It is involved in a wide spectrum of physiological functions, from sleep and sedation to convulsions. A defect in neurotransmission involving GABA in schizophrenia was first propsed in early 1970s, based on neuropathologcial evidence, yet there is a lack of molecular genetic evidence.

Recently, we carried out a pilot study on a region of the GABA-A receptor β2 subunit gene on chromosome 5 and found significant association for single nucleotide polymorphisms (SNPs) in the gene sequence with occurrence of schizophrenia. The current proposal aims to validate this important finding and to conduct a thorough scanning of the complete gene sequences of the GABA-A receptor subunit genes in this chromosomal region, including the three major subunits α1, β2 and γ2. We shall collect samples from Hong Kong Chinese subjects for a case-control study using haplotype maps and comparing the SNP haplotype frequencies in the receptor genes, and hence examine whether these genes are in association with schizophrenia, or other schizophrenia-spectrum disorders, including Alzheimer's disease presenting with psychotic symptoms.

Based on the observation that patients suffering from the catatonic subtype of schizophrenia respond particularly well to benzodiazepines, which bind specifically to GABA-A receptors, we shall also perform data analysis in terms of correlating SNP association with schizophrenia subtypes. Association of GABA-A receptor genes with schizophrenia would be a major step forward to determining whether these genes are susceptibility genes for schizophrenia, thereby paving the way to more effective diagnosis and treatment for this debilitating disease.


Eligibility criteria: Inclusion Criteria:

(For patients:)

* Diagnosis of schizophrenia under DSM-IV guidelines.

Exclusion Criteria:

(For controls:)

* Subjects who are known to have blood transmitted disease.
* Past or current alcohol and /or substance abuse.
* Past or current major medical and neurological conditions.

(For patients:)

* As for controls, excepr 3. "neurological conditions" does not include schizophrenia.

Primary outcomes:
Secondary outcomes:
Other outcomes:
Locations:
city: Hong Kong
country: China
facility: NTE Cluster under HA
city: Hong Kong
country: China
facility: Shatin Hospital
city: Hong Kong
country: China
facility: Tai Po Hospital
city: Hong Kong
country: China
facility: The Hong Kong University of Science and Technology
Study officials:
affiliation: Department of Psychiatry, Tai Po Hospital
name: Dicky WS Chung, Dr
role: PRINCIPAL_INVESTIGATOR
References: