A rare germline BMP15 missense mutation causes hereditary ovarian immature teratoma in human

Ovarian immature teratomas (OITs) are malignant tumors originating from the ovarian germ cells that mainly occur during the first 30 y of a female's life. Early age of onset strongly suggests the presence of susceptibility gene mutations for the disease yet to be discovered. Whole exon sequencing was used to screen pathogenic mutations from pedigrees with OITs. A rare missense germline mutation (C262T) in the first exon of the BMP15 gene was identified. In silico calculation suggested that the mutation could impair the formation of mature peptides. In vitro experiments on cell lines confirmed that the mutation caused an 84.7% reduction in the secretion of mature BMP15. Clinical samples from OIT patients also showed a similar pattern of decrease in the BMP15 expression. In the transgenic mouse model, the spontaneous parthenogenetic activation significantly increased in oocytes carrying the T allele. Remarkably, a mouse carrying the T allele developed the phenotype of OIT. Oocyte-specific RNA sequencing revealed that abnormal activation of the H-Ras/MAPK pathway might contribute to the development of OIT. BMP15 was identified as a pathogenic gene for OIT which improved our understanding of the etiology of OIT and provided a potential biomarker for genetic screening of this disorder.

Two novel mutations in exon 2 of bone morphogenetic protein (BMP) 15 gene in Pakistani infertile females

Objective

To determine the proportion of fertility in Pakistani infertile females and discover if there are considerable connection among BMP15 gene polymorphism, follicle maturation and hormonal regulation in Pakistani infertile females.

Methods

All selected participants were initially examined through follicle-stimulating hormones (FSH), luteinizing hormone (LH), thyroid-stimulating hormone (TSH), Prolactin, and Trans-vaginal scan (TVS). BMP15 gene polymorphism among infertile and fertile females was done by extracted Genomic DNA from whole blood. Sanger sequencing was performed for the identification of mutation in exons-intron boundaries of the BMP15 gene. Bioinformatics tools were used to assess the protein structure.

Results

The total five mutations including two novel missense variants of BMP15 in exon 2, whereas three previously reported i.e. two cosmic mutations (c.615delC), (c.584InsG) and one frame shift mutations (c.635delA) were also observed. The first novel mutation was found at (c.1038InsGG) (p.346Gln < Gly) in which the insertion of GG at DNA position 1038 of exon 2 resulting in a substitution of glutamine into glycine at 346th amino acid of BMP15 protein. The second novel variant (c.1049delT) (p. Ser334Pro) was also observed in exon 2 of the BMP15 gene, which substituted serine into proline at 334th amino acid of the BMP15 protein.

Conclusion

It is concluded that there are various missense mutations present in exon 2 of the BMP15 gene of Pakistani infertile females, consequently expected function of protein changes due to change in codons of amino acids. Provean and SIFT suggest the two novel variants as potentially deleterious. Although three other variants were also found in Pakistani infertile females which were previously reported. These mutations may result in early blockage of folliculogenesis and ovaries become streaky. Further research is required to resolve the actual allusion of these variations in the BMP15 gene.

Age-related decline in the expression of GDF9 and BMP15 genes in follicle fluid and granulosa cells derived from poor ovarian responders

Background

Growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) genes play important roles in folliculogenesis. Altered expression of the two have been found among patients with poor ovarian response (POR). In this prospective cohort study, we have determined the expression of the GDF9 and BMP15 genes in follicle fluid (FF) and granulosa cells (GCs) derived from poor ovarian responders grouped by age, and explored its correlation with the outcome of in vitro fertilization and embryo transfer (IVF-ET) treatment.

Methods

A total of 196 patients with POR were enrolled from a tertiary teaching hospital. The patients were diagnosed by the Bologna criteria and sub-divided into group A (< 35 year old), group B (35–40 year old), and group C (> 40 year old). A GnRH antagonist protocol was conducted for all patients, and FF and GCs were collected after oocyte retrieval. Expression of the GDF9 and BMP15 genes in the FF and GCs was determined with enzyme-linked immunosorbent assay (ELISA), quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting.

Results

Compared with group C, groups A and B had significantly more two pronuclei (2PN) oocytes and transplantable embryos, in addition with higher rates of implantation and clinical pregnancy (P <  0.05). The expression level of GDF9 and BMP15 genes in the FF and GCs differed significantly among the three groups (P <  0.05), showing a trend of decline along with age. The ratio of GDF9/BMP15 mRNA levels were similar among the three groups (P > 0.05). The relative levels of GDF9 and BMP15 proteins in GCs have correlated with the relative mRNA levels in GCs and protein concentrations in FF (P <  0.05).

Conclusions

For poor ovarian responders, in particular those over 40, the expression of GDF9 and BMP15 is declined along with increased age and in accompany with poorer oocyte quality and IVF outcome, whilst the ratio of GDF9/BMP15 mRNA levels remained relatively constant.

Trial registration

Chinese Clinical Trial Registry Center (ChiCTR1800016107). Registered on 11 May 2018.

Use of Bone Morphogenetic Protein 15 Polymorphisms to Predict Ovarian Stimulation Outcomes in Infertile Brazilian Women

AIMS

Polymorphisms in the gene encoding bone morphogenetic protein 15 (BMP15) can result in inhibited secretion or lowered bioactivity of the BMP15 protein. BMP15 levels are associated with follicle-stimulating hormone receptor (FSHR) action on granulosa cells, wherein FSHR increases the sensitivity of ovarian follicles to follicle-stimulating hormone (FSH). In this study we evaluated the BMP15 polymorphisms A905 > G/rs3897937, C901 > T/rs17003221, and C-9 > G/rs3810682 in infertile Brazilian women in terms of anti-Mullerian hormone (AMH), FSH, and estradiol serum levels, as well as controlled ovarian hyperstimulation response and assisted reproduction outcomes.

METHODS

A cross-sectional study comprising 186 infertile women who underwent the first cycle of high complexity assisted reproduction treatment was conducted using the TaqMan assay for quantitative polymerase chain reaction genotyping. Serum AMH, FSH, and estradiol levels were measured by enzyme-linked immunosorbent assay.

RESULTS

For C901 > T (rs17003221) carriers, there was a statistically significant difference among carriers of a polymorphic BMP15 genotype (TT) and the estradiol concentration. These women had higher estradiol levels than women who had homozygous wild type or heterozygous genotypes. There was also a positive correlation between serum AMH and the C-9 > G (rs3810682) polymorphism, wherein women carrying both polymorphic alleles (homozygous, GG) had higher average AMH levels than heterozygous women. However, none of the three polymorphisms studied showed a statistically significant correlation with assisted reproduction outcome.

DISCUSSION

Oocytes are known to secrete factors that regulate follicular development and oocyte maturation. Abnormal expression of these factors may thus be involved in follicular development disorders. A recent study highlighted the importance of BMP15 in regulating ovulation rates in sheep and that heterozygous deletions in the -9C > G polymorphism reduced BMP15 concentrations, increased granulosa cell FHSR mRNA levels, elevated estrogen secretion, and activated production of stem cell factors. In this study we found that BMP15 polymorphisms affected estrogen and AMH levels.

CONCLUSION

BMP15 polymorphisms are not correlated with ovarian stimulation and assisted reproduction outcomes in infertile Brazilian women.