Human Genetics

, Volume 119, Issue 4, pp 436–443

Long-term persistence of both functional and non-functional alleles at the leukocyte immunoglobulin-like receptor A3 (LILRA3) locus suggests balancing selection

Authors

  • Kouyuki Hirayasu
    • Tokyo Metropolitan Red Cross Blood Center
    • Department of Human Genetics, Graduate School of MedicineUniversity of Tokyo
  • Jun Ohashi
    • Department of Human Genetics, Graduate School of MedicineUniversity of Tokyo
  • Koichi Kashiwase
    • Tokyo Metropolitan Red Cross Blood Center
  • Minoko Takanashi
    • Tokyo Metropolitan Red Cross Blood Center
  • Masahiro Satake
    • Tokyo Metropolitan Red Cross Blood Center
  • Katsushi Tokunaga
    • Department of Human Genetics, Graduate School of MedicineUniversity of Tokyo
    • Tokyo Metropolitan Red Cross Blood Center
Original Investigation

DOI: 10.1007/s00439-006-0152-y

Cite this article as:
Hirayasu, K., Ohashi, J., Kashiwase, K. et al. Hum Genet (2006) 119: 436. doi:10.1007/s00439-006-0152-y

Abstract

The leukocyte immunoglobulin-like receptor (LILR) family consists of 13 loci, and a number of variations have been identified in these genes. Some polymorphisms of the LILR genes are reported to be associated with susceptibility to diseases such as rheumatoid arthritis and multiple sclerosis. LILRA3, one of the LILR genes, exhibits a presence or absence variation due to a 6.7-kb deletion in various populations. In this study, variation screening of the LILRA3 gene revealed high allele frequency of the 6.7-kb LILRA3 deletion (71%) in Japanese, in contrast to the frequency reported for the other populations. In addition, we identified a splice acceptor mutation in intron 1 with allele frequency of 19%, resulting in three alternatively spliced isoforms. Surprisingly, all of these isoforms were found to contain premature termination codons (PTCs) in the exon 3. Taken together, approximately 80% of Japanese lack functional LILRA3 alleles. The maximum likelihood coalescent analysis suggested that two major lineages, functional alleles and PTC-containing alleles, have been maintained for 2.75 million years in humans. These results prompted us to hypothesize that balancing selection had maintained both the functional and non-functional alleles at the LILRA3 locus. This hypothesis is consistent with the observation that the 6.7-kb LILRA3 deletion is detected worldwide in the presence of functional LILRA3 alleles.

Copyright information

© Springer-Verlag 2006