Recurrent spontaneous abortions patients have more -14 bp/+14 bp heterozygotes in the 3'UT region of the HLA-G gene in a Chinese Han population.

Although human leukocyte antigen (HLA)-G gene polymorphism is low, it may influence levels of protein expression and, in some cases, has been associated with pregnancy diseases. Apart from the 23 HLA-G alleles, including a null allele known as HLA-G*0105N, a 14-bp deletion or insertion in the 3'UT region also contributes to the HLA-G gene polymorphism. In order to discover any correlation between the 14-bp deletion polymorphism and pregnancy diseases, we isolated the genomic DNA from 24 recurrent spontaneous abortions (RSA) patients and 88 normal fertile control individuals using the salted out method. Exon-8 of HLA-G gene of the two groups was amplified by polymerase chain reaction, respectively, and analyzed by electrophoresis on 9% nondenaturing polyacrylamide gel and stained with ethidium bromide. Differences between the two groups were compared using the chi(2) test. The results were there was no significant difference in allelic frequencies of 14-bp deletion polymorphism between normal control and RSA patients; frequency of -14 bp/+14 bp heterozygotes was significantly increased in RSA patients as compared with normal fertile controls. Our results are similar to a study of Indian women but contradictory to a study of Danish women. This discrepancy may be due to ethnic differences.