J Korean Neuropsychiatr Assoc.  1999 Sep;38(5):1130-1136.

An Association Study of Schizophrenics and Their Clinical Variables with Tryptophan Hydroxylase Gene Polymorphism

• Cho HS
• Lee SP
• Toh KY
• Paik IH

Abstract

OBJECTIVES: The genetic polymorphism of tryptophan hydroxylase (TPH) the rate-limiting enzyme in the biosynthesis of serotonin, has been to be related with various psychiatric disorders such as bipolar disorders. However, the role of TPH gene polymorphism in schizophrenia is totally unknown. Author examined the association of the TPH gene polymorphism with the development and the clinical variables of schizophrnia.
METHODS
Genomic DNAs from 217 schizophrenic patients and 236 healthy controls were isolated, and TPH gene was amplified using PCR. Amplified TPH DNA was digested with NheI and the polymorphism was examined by electrophoresis on agarose gel.
RESULTS
The allele frequencies and the genotypes of TPH gene were not significantly different between the schizophrenics and the control groups. They were also not associated with most of the clinical variables of schizophrenia such as subtypes, suicidal ideation, age at onset, and family histories. Among the clinical variables, only suicidal rate was highly correlated with genotype 218C/C.
CONCLUSION
We found possible association of the suicical behavior with 218C/C polymorphism. However, it seems that A218C polymorphism of TPH gene does not associated with the development and other clinical variables of schizophrenia.

Keyword

Schizophrenia; Tryptophan hydroxylase; A218C polymorphism; Association; Suicidal behavior

MeSH Terms

Bipolar Disorder
DNA
Electrophoresis
Gene Frequency
Genotype
Humans
Polymerase Chain Reaction
Polymorphism, Genetic
Schizophrenia
Sepharose
Serotonin
Suicidal Ideation
Tryptophan Hydroxylase*
Tryptophan*
DNA
Sepharose
Serotonin
Tryptophan
Tryptophan Hydroxylase