The association of Q472H variant in the KDR gene with recurrent pregnancy loss in Southern Iran: A case-control study

BACKGROUND: Recurrent spontaneous abortion (RSA) often remains unclear and can be burden for the patient and time consuming for clinician. RSA may initiates from a genetic or non-genetic factors. It is well known that the quality of placental circulation is critical for implantation and embryo development. Because of angiogenic effects of VEGF–KDR pathway on placenta, the genes involved in this pathway (the KDR or VEGFR genes) are thought to be linked with RSA. OBJECTIVE: The aim of this study was to investigate the relationship between Gln472His (A/T) polymorphism of the KDR gene with RSAs in southern Iran. MATERIALS AND METHODS: In this case-control study, 50 aborted embryonic tissue obtained from fetuses and 50 umbilical cord blood of newborn babies were studied. Fetal sample from mothers with history of at least two consecutive miscarriages and controls from mothers who had at least one full-term infants born were taken. Genomic DNA was extracted by using PureLink genomic DNA kit (Life Technologies, CA). The Rotor-Gene Q real-Time PCR machine and High-resolution melting curve analysis (HRM) technique were used for genotyping. RESULTS: Based on the AA genotype as reference, it is shown that the T allele (OR = 2.447, 95% CI = 1.095–5.468, p = 0.029) as well as AT heterozygote genotype was significantly associated with an increased risk of miscarriage (OR = 2.824, 95% CI = 1.210-6.673, p = 0.016). CONCLUSION: A positive correlation between Q472H polymorphism of the KDR gene and RSA may be the cause in southern Iran.