Genetic links between HLA-G and recurrent pregnancy loss: a global perspective

Recurrent spontaneous abortion (RSA), defined as the loss of three or more fetuses during the first trimester of pregnancy, is a significant reproductive health issue. The Human Leukocyte Antigen (HLA)-G, a non-classical major histocompatibility complex (MHC) class I molecule, plays a crucial role in maternal-fetal immune tolerance. This study investigates the relationship between HLA-G alleles and RSA across various populations globally. Allelic frequencies were analyzed using data from the Anthony Nolan and Allele Frequencies databases, focusing on populations with genetic ties to Colombia due to historical migration patterns. Results indicate that the HLA-G01:01 allele is most prevalent in Denmark, Germany, Portugal, and the United States, with frequencies of 56.7%, 87.47%, 77.19%, and 79.8%, respectively. Conversely, the HLA-G01:03 and HLA-G01:05N alleles are the least frequent, with HLA-G01:05N particularly associated with RSA. The study underscores the importance of HLA-G in pregnancy outcomes and suggests that genetic screening for specific HLA-G alleles in women with a history of RSA could provide insights into the risk factors and mechanisms underlying recurrent pregnancy loss.