Find out “Study links gene variant to miscarriage through disrupted chromosome pairing” A low-frequency missense variant in the SYCE2 gene has been found to increase the risk of pregnancy loss by 22%.
This gene variant is linked to an increased risk of miscarriage through disrupted chromosome pairing, specifically affecting the recombination between homologous chromosomes during meiosis, the process of generating egg and sperm cells.
The study, published in Nature Structural and Molecular Biology, involved a genome-wide association study with over 114 thousand women from multiple countries who have experienced pregnancy loss.
The findings suggest that the variant’s effect on recombination may lead to an increased risk of pregnancy loss, particularly in cases where the effect may be more extreme, although further research is needed to fully understand its impact.
Additionally, variants in other genes such as SYCP3 have also been implicated in altering the pairing and recombination of homologous chromosomes during meiosis, potentially leading to a high risk of recurrent pregnancy loss.
Chromosomal abnormalities, including structural variations and aneuploidy, have been identified as major causes of miscarriages, with approximately 50–70% of early miscarriages being associated with chromosome abnormalities.
In summary, genetic variants impacting the recombination and pairing of homologous chromosomes during meiosis, such as the SYCE2 and SYCP3 gene variants, can contribute to an increased risk of miscarriage by disrupting normal chromosomal processes. These findings highlight the importance of understanding the genetic factors associated with pregnancy loss and recurrent miscarriage.
Here are the key findings of the study:
- A rare variant in the SYCE2 gene increases the risk of pregnancy loss by 22%. This is the first identified gene variant with such a substantial effect on miscarriage risk.
- The SYCE2 variant disrupts chromosome pairing during meiosis, the cell division process that creates egg and sperm cells. This disruption affects recombination, the swapping of genetic material between homologous chromosomes, which is essential for healthy gamete development.
- The variant’s effect on recombination is amplified in longer chromosomes. This suggests that it may have an even greater impact on miscarriage risk, as chromosomal errors are more common in longer chromosomes.
- The study may underestimate the true impact of the variant. It only included women who experienced confirmed pregnancy loss, not those with undetected early miscarriages.
- Despite increasing miscarriage risk, the SYCE2 variant persists in the population. This suggests that there may be selective pressures that outweigh its detrimental effects.
These findings provide valuable insights into the genetic factors that contribute to miscarriage and open doors for further research into potential prevention strategies.
What are other genetic factors that can cause miscarriage
Genetic factors can significantly contribute to miscarriages. Here are some genetic factors that can cause miscarriage:
- Chromosomal Abnormalities: Approximately 50% of first-trimester miscarriages are due to chromosomal abnormalities in the fetus, such as trisomies, monosomies, and structural chromosome anomalies.
- Single Gene Defects: Mutations in specific genes can lead to genetic diseases or birth defects, potentially causing miscarriage. These mutations can affect various biological processes, including musculoskeletal development, immune system regulation, and blood clotting.
- Chromosomal Imbalance: Extra or missing genetic material, leading to chromosomal imbalance, can cause miscarriage. This imbalance can result from a change (variant) in one or more genes on the chromosomes.
- Translocations: Abnormalities in the structure of chromosomes, such as translocations, in either partner can be a cause of recurrent miscarriage.
Genetic testing of the couple attempting pregnancy can help identify these genetic factors, especially in cases of recurrent miscarriages. It is essential to understand the genetic components of miscarriage to provide appropriate medical care and counseling to affected individuals and couples.
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Journal References
- Luis Alejandro Arias-Sosa et al., 2018. Genetic and epigenetic variations associated with idiopathic recurrent pregnancy loss. Journal of Assisted Reproduction and Genetics doi: 10.1007/s10815-017-1108-y
- Huihua Rao Et al., 2023. Analysis of chromosomal structural variations in patients with recurrent spontaneous abortion using optical genome mapping. Genomic Assay Technology. https://doi.org/10.3389/fgene.2023.1248755
- Priti Singh et al., 2021. Human MLH1/3 variants causing aneuploidy, pregnancy loss, and premature reproductive aging. Nature Communications . https://www.nature.com/articles/s41467-021-25028-1
