OBJECTIVE: To examine the functional change of Umodl1 as a result of polymorphism, and establish a correlation of Umodl1 polymorphism to reduced female fertility.DESIGN: Nucleotide variations at position 820 of Umodl1, A820C and A820G, are of particular interest as they change the amino acid from a neutral Asn to charged His and Asp, respectively; which may affect granulosa cell growth. Proliferative activities of the polymorphic Umodl1 proteins were evaluated by in vitro transfection assay. Umodl1polymorphisms in IVF patients were tested by CEL1 nuclease assay.MATERIALS AND METHODS: 1) In vitro transfection. Three groups of MCF7 cells were transfected with a CMV-Umodl1 vector containing one of the three alleles at positive 820, and cultured for 3 days in medium with 20IU/l FSH and 10-9M E2. Control group 1(CG1) is MCF7 cells cultured in medium with E2 alone. MCF7 cells cultured in medium containing both FSH and E2 were used as CG2. CG3 is transfected cells cultured in medium without FSH and E2. Cell proliferation was examined by MTT assay. 2) CEL1 nuclease assay. Genomic DNA samples from 196 patients were PCR-amplified around the 6th exon. Reference sample was derived from an A allele; patient samples were used as test samples. Hybridization and digestion were performed as suggested by Transgenomic, Inc.RESULTS: FSH augmented the action of E2 by 2 fold in MCF7 cell proliferation. A further 30% increase was seen in the MCF7 cells carrying an A820 allele; however, only a 13% increase was observed in the cells with a C allele. The G allele shows no synergistic effect on FSH. In general population, the frequency of the C or G allele is 0.16% and 0.049%, respectively. Three patients (1.7%) with C/C alleles and five (2.6%) with A/C alleles were identified. No G allele was found.CONCLUSIONS: Polymorphic change at position 820 from A to C/G weakens the synergistic effect of Umodl1 on the proliferative action of FSH/E2 to stimulate FSHr+ cell growth. A higher frequency (p<0.05) of a C allele were observed in IVF patients. OBJECTIVE: To examine the functional change of Umodl1 as a result of polymorphism, and establish a correlation of Umodl1 polymorphism to reduced female fertility. DESIGN: Nucleotide variations at position 820 of Umodl1, A820C and A820G, are of particular interest as they change the amino acid from a neutral Asn to charged His and Asp, respectively; which may affect granulosa cell growth. Proliferative activities of the polymorphic Umodl1 proteins were evaluated by in vitro transfection assay. Umodl1polymorphisms in IVF patients were tested by CEL1 nuclease assay. MATERIALS AND METHODS: 1) In vitro transfection. Three groups of MCF7 cells were transfected with a CMV-Umodl1 vector containing one of the three alleles at positive 820, and cultured for 3 days in medium with 20IU/l FSH and 10-9M E2. Control group 1(CG1) is MCF7 cells cultured in medium with E2 alone. MCF7 cells cultured in medium containing both FSH and E2 were used as CG2. CG3 is transfected cells cultured in medium without FSH and E2. Cell proliferation was examined by MTT assay. 2) CEL1 nuclease assay. Genomic DNA samples from 196 patients were PCR-amplified around the 6th exon. Reference sample was derived from an A allele; patient samples were used as test samples. Hybridization and digestion were performed as suggested by Transgenomic, Inc. RESULTS: FSH augmented the action of E2 by 2 fold in MCF7 cell proliferation. A further 30% increase was seen in the MCF7 cells carrying an A820 allele; however, only a 13% increase was observed in the cells with a C allele. The G allele shows no synergistic effect on FSH. In general population, the frequency of the C or G allele is 0.16% and 0.049%, respectively. Three patients (1.7%) with C/C alleles and five (2.6%) with A/C alleles were identified. No G allele was found. CONCLUSIONS: Polymorphic change at position 820 from A to C/G weakens the synergistic effect of Umodl1 on the proliferative action of FSH/E2 to stimulate FSHr+ cell growth. A higher frequency (p<0.05) of a C allele were observed in IVF patients.