Polymorphisms of tryptophan hydroxylase gene and the symptomatology of schizophrenia: an association study: PDF OnlyPolymorphisms of tryptophan hydroxylase gene and the symptomatology of schizophrenia: an association studyShinkai, Takahiro; Ohmori, Osamu; Suzuki, Takashi; Kojima, Hideki; Hori, Hiroko; Terao, Takeshi; Nakamura, JunAuthor Information Department of Psychiatry, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan Correspondence to Takahiro Shinkai MD, Department of Psychiatry, School of Medicine, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan. E-mail:[email protected] Received 14 June 2000; accepted 6 November 2000 Psychiatric Genetics: December 2000 - Volume 10 - Issue 4 - p 165-171 Buy Abstract Serotonergic neurotransmission may be involved in the etiology of schizophrenia. We systematically searched for human tryptophan hydroxylase (TPH) coding polymorphisms, and detected a novel pentanucleotide repeat deletion polymorphism (GTTTT)4/5 in TPH intron 1b. We also confirmed A779C intron 7. Neither polymorphism showed a significant association with schizophrenia (182 patients with schizophrenia, 148 controls). A significant association, however, between A779C genotypes and the total Manchester Scale (MS) scores was found in male patients (P= 0.045). Subsequently, a significant association was also found between A779C genotypes and the MS negative symptoms scores in male patients (P= 0.030). These results suggest that the TPH gene may play a role in the negative symptoms in male patients with schizophrenia. © 2000 Lippincott Williams & Wilkins, Inc.