Point mutations within 663-666 bp of intron 6 of the human TDO2 gene, associated with a number of psychiatric disorders, damage the YY-1 transcription factor binding site.

Single base mutations G-->A at position 663 and G-->T at position 666 of intron 6 of the human tryptophan oxygenase gene (TDO2) are associated with a variety of psychiatric disorders [Comings, D.E. et al. (1996) Pharmacogenetics 6, 307-318]. Binding of rat liver nuclear extract proteins to synthetic double-strand oligonucleotides corresponding to three allelic states of the region between 651 bp and 680 bp of human TDO2 intron 6 has been studied by gel shift assay. It has been demonstrated that to each allelic state of the region there corresponds a specific set of proteins that interacts with it. With the aid of computer analysis and using specific anti-YY-1 antibodies it has been shown that both mutations damage the YY-1 transcription factor binding site.