NCIt definition : HTR2A-C Allele is a variant form of 20-kb 3-exon human HTR2A Gene (GPCR1/5HT2 Family),
which encodes Serotonin 5-HT-2A Receptor, a conserved integral membrane 5-HT/serotonin
receptor protein involved in tracheal smooth muscle contraction, bronchoconstriction,
and control of aldosterone production by association with G proteins that activate
a PI-calcium second messenger system. 5-HT is a biogenic hormone that affects specific
receptors as a neurotransmitter, hormone, or mitogen. HTR2A contains several polymorphic
sites. Different alleles differ in the concentration of RNA and protein product of
5HTR2A. HTR2A-C Allele contains a single-nucleotide polymorphism (102 T C) in an intron
and is expressed at a lower level than the 102 C T allele.;