Linkage Mapping of the Human Thromboxane A2Receptor (TBXA2R) to Chromosome 19p13.3 Using Transcribed 3′ Untranslated DNA Sequence Polymorphisms

The actions of thromboxane A2as a prostaglandin mediator are dependent on its recently cloned and sequenced receptor. The identification and characterization of DNA polymorphisms in the thromboxane A2receptor (TBXA2R) will advance the study of this gene as a candidate in a number of medical disorders. We amplified a 573-nucleotide fragment of the transcribed 3′ untranslated region of the TBXA2R gene using the polymerase chain reaction (PCR) and the published cDNA sequence. This region was found to contain two sequence polymorphisms within an Alu. These DNA polymorphisms were demonstrated using an efficient method of direct solid-phase sequence analysis. Three of the four expected alleles were observed in the CEPH families. TBXA2R was localized to chromosome 19 by PCR amplification in a series of monochromosomal human/rodent somatic cell hybrids. Linkage mapping places TBXA2R closest to the anonymous marker D19S120, with a maximal LOD = 19.55, at a θ = 0.05 in the CEPH panel of DNAs. Multipoint linkage analysis places TBXA2R between the markers D19S120 and PMS207 on the telomeric end of chromosome 19p13.3.