T102

The SNP is a synonymous substitution located in exon 1 of the gene where it is involved in coding the 34th amino acid as serine.
As 5-HT2A is a neuroreceptor the SNP has been investigation in connection with brain functions and neuropsychiatric disorders, and it is perhaps the most investigated SNP for its gene. Two other SNPs in HTR2A have also received much attention: rs6311 and His452Tyr (rs6314).

A less well investigated SNP of this gene is rs7997012.
Meta-analyses seem to indicate that the SNP is not directly associated with schizophrenia, not with Alzheimer's Disease, and two initial studies seem to indicate that it is not associated with Parkinson's Disease.
There have been multiple studies of the effect of the SNP on clozapine treatment response in schizophrenia. A meta-analysis published in 1998 found an association.
Individual studies
Many individual studies investigate possible effects of the polymorphism on, say, a personality trait or a disorder. "Meta-analysis of studies on genetic variation in 5-HT2A receptors and clozapine response"."Serotonin 2A receptor gene is associated with personality traits, but not to disorder, in patients with borderline personality disorder". Unschuld, Marcus Ising, Angelika Erhardt, Susanne Lucae, Stefan Kloiber, Martin Kohli, Daria Salyakina, Tobias Welt, Nikola Kern, Roselind Lieb, Manfred Uhr, Elisabeth B.

"Polymorphisms in the serotonin receptor gene HTR2A are associated with quantitative traits in panic disorder". "Lack of association between three serotonin genes and suicidal behavior in Chinese psychiatric patients"."Genetic variations in the serotonin 5-HT2A receptor gene (HTR2A) are associated with rheumatoid arthritis". "Polymorphisms of the serotonin-2A receptor and catechol-O-methyltransferase genes: a study on fibromyalgia susceptibility".

"5-HT2A and 5-HT2C receptor polymorphisms and psychopathology in late onset Alzheimer’s disease".