The alleles of PECAM-1

Previous studies have reported the existence of eleven different single nucleotide polymorphisms (SNPs) within human PECAM-1 mRNA, several of which have recently been associated with disease. Though SNPs in the PECAM-1 gene have been known for some time, the genetic background on which they exist, and their association into distinct allelic isoforms has not yet been established. To identify the major allelic isoforms of PECAM-1, we determined the nucleotide sequence of individual full-length cloned cDNAs derived from anonymous, unrelated volunteer individuals. Initial sequence analysis of 34 alleles from 17 individuals confirmed the presence of two distinct human PECAM-1 alleles (L98S536R643 and V98N536G643) within the human population. Each of these were found, upon more detailed analysis, to be superimposed on a previously unreported a2479g nucleotide polymorphism within the 3′ untranslated region (3′UTR) that occurred on both allelic isoforms — yielding a total of four major alleles. Multiplex Luminex bead analysis of an additional 259 individuals allowed identification of 117 individuals homozygous for either the L98S536 or V98N536 allele, and sequence analysis around the R643G and a2479g polymorphic sites permitted accurate determination of significant differences in the gene frequencies of LSRa, LSRg, VNGa, and VNGg among Caucasian individuals. Identification of these PECAM-1 allelic isoforms should facilitate future detailed examination of PECAM-1-related disease associations, and may help resolve previously disparate results.