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Association of tryptophan 2,3 dioxygenase gene polymorphism with autism
Author(s) -
Nabi Rafiqun,
Serajee Fatema J.,
Chugani Diane C.,
Zhong Hailang,
Huq A.H.M. Mahbubul
Publication year - 2003
Publication title -
american journal of medical genetics part b: neuropsychiatric genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.393
H-Index - 126
eISSN - 1552-485X
pISSN - 1552-4841
DOI - 10.1002/ajmg.b.20147
Subject(s) - genetics , transmission disequilibrium test , haplotype , gene , serotonin transporter , autism , biology , tryptophan , tryptophan hydroxylase , serotonin , candidate gene , single nucleotide polymorphism , allele , genotype , medicine , serotonergic , psychiatry , receptor , amino acid
Although elevation of blood and platelet serotonin has been documented in autism, genetic analyses of serotonin transporter gene have given conflicting results. Tryptophan 2,3 dioxygenase (TDO2) is the rate‐limiting enzyme in the catabolism of tryptophan, the precursor of serotonin. A mutation that results in decreased activity of the TDO2 can decrease catabolism of tryptophan and increase the level of whole body serotonin. As such it is a potential candidate gene for autism. We have investigated five single nucleotide polymorphisms in the TDO2 gene for association with autistic disorder. One hundred and ninety six multiplex autistic disorder families were tested using transmission disequilibrium test. There was a significant difference in the transmission of a promoter variant to autistic subjects ( P = 0.0006). Haplotype analysis also demonstrated significant difference in the transmission of TDO2 haplotypes to autistic subjects ( P = 0.0027). Our results suggest the presence of a susceptibility mutation in the TDO2 or a nearby gene, but may also represent a chance finding. © 2003 Wiley‐Liss, Inc.