TPH1 - Clinical Significance

Clinical Significance

Tryptophan hydroxylase is important for the brain. However, Tph1 is not detected in the brain. Nevertheless the effect of variations in the TPH1 gene on brain-related variables, such as personality traits and neuropsychiatric disorders, has been studied. For example, one study found an association between a polymorphism in the gene with impulsive-aggression measures, while a case-control study could find no association between polymorphisms and Alzheimer's Disease. One human mutant of TPH1, A218C found in intron 7, is highly associated with schizophrenia. Introns are regions of DNA that do not code for the amino acid sequence of a protein and were long considered to be 'junk DNA' lacking purpose. The correlation of an intron mutation with schizophrenia is significant because it suggests that introns have an important role in translation, transcription, or another, possibly unknown, aspect of the production of proteins from DNA.