Allelic variations of the human histamine H2 receptor gene

The gene encoding the human histamine H2 receptor (H2R) has previously been cloned and sequenced from gastric cDNA. Following PCR amplification of a fragment of the H2R gene from total human DNA, three single nucleotide base substitutions were observed and confirmed when compared with the previously published sequence. One of these base changes introduces an additional TaqI restriction endonuclease site in the coding portion of the gene. PCR amplification of human H2R gene fragments followed by cleavage with TaqI demonstrated the existence of allelic variation of the human H2R gene.