RESUMO
Several genetic factors have been found to be associated with recurrent pregnancy loss (RPL). However, not many attempts have been made to associate the mitochondrial DNA (mtDNA) variations with RPL. Therefore, we have analyzed the complete mtDNA of 100 women with RPL and 12 aborted fetal tissues. Our analysis revealed a total of 681 variations, most of which were in NADH Dehydrogenase (ND) genes that encode mitochondrial enzyme Complex I. Presence of T4216C variation (ND1 gene) in 9% of the RPL women and several pathogenic, and novel mutations suggest the role of mtDNA variations in RPL.
Assuntos
Aborto Habitual/genética , DNA Mitocondrial/genética , Polimorfismo Genético , Adulto , Complexo I de Transporte de Elétrons/genética , Feminino , Frequência do Gene , Humanos , Índia , Proteínas Mitocondriais/genética , GravidezRESUMO
OBJECTIVE: To establish the risk associated with mutations in the coding region of GDF9 gene in Indian women with ovarian failure. DESIGN: This case-control study was designed for mutational analysis of the GDF9 coding region in a cohort of women with premature ovarian failure (n = 127), primary amenorrhea (n = 58), and secondary amenorrhea (n = 10) compared with controls (n = 220). RESULTS: This case-control study revealed eight mutations in the GDF9 gene, including five novel mutations: c.1-8C>T, c.199A>C (p.Lys67Glu), c. 205C>T, c.646G>A (p.Val216Mat), and c.1353C>T, and three documented mutations: c.398-39C>G, c.447C>T, and c.546G>A. Missense mutation c.199A>C was present in 4 of 127 premature ovarian failure (POF) cases and 1 of 10 secondary amenorrhea cases. The c.646G>A mutation was present in two POF cases. Both missense mutations were absent in controls. Genotype distribution of c.447C>T was significantly different in POF cases than controls (chi(2) = 5.93, P = 0.05). We chose two frequent single-nucleotide polymorphisms (c.398-39C>G, c.447C>T) for haplotyping and found that the C-T haplotype was significantly higher in patients (P = 0.03), whereas the C-C haplotype was representative of the control group. CONCLUSIONS: We report two rare missense mutations, c.199A>C and c.646G>A, which are associated with ovarian failure. The presence of the c.447>T mutation might indicate a higher risk for POF. Haplotype C-T was significantly associated with ovarian failure, whereas the C-C haplotype was representative of the control group.
