Scientists from deCODE genetics, a subsidiary of Amgen, along with researchers from Iceland, Denmark, and the United States, have conducted a groundbreaking study shedding light on the genetics of pregnancy loss. While previous research has established that chromosomal abnormalities are a significant cause of miscarriages, the biological mechanisms behind pregnancy losses, both with and without chromosomal errors, have remained elusive.
In this study, over 114 thousand women from multiple countries who have experienced pregnancy loss participated, making it a comprehensive genome-wide association study. The researchers tested a staggering 50 million sequence variants to uncover potential genetic links to pregnancy loss.
One particular finding stood out – a low-frequency missense variant in the SYCE2 gene was discovered to increase the risk of pregnancy loss by a staggering 22%. This gene is responsible for producing a protein complex that plays a crucial role in the alignment of homologous chromosomes during meiosis, the process of generating human egg and sperm cells.
Interestingly, previous research by deCODE scientists highlighted the association of this missense variant with recombination phenotypes in chromosomes inherited from the mother. Recombination, an essential step in meiosis, allows for genetic diversity and proper alignment of chromosomes.
The effect of this variant on recombination was further investigated, revealing that it impacts the positioning of crossovers in proportion to the length of the chromosomes. In other words, the effect was more pronounced in longer chromosomes. Moreover, this effect on recombination was measured in live-born individuals, suggesting its potential influence on successful pregnancies.
The researchers propose that this variant’s impact on recombination may be more extreme in pregnancies that end in miscarriage, potentially contributing to pregnancy loss. However, it’s worth noting that the association with pregnancy loss does not account for early gestational losses that occur before pregnancy can be detected, potentially underestimating its overall effect on pregnancy success.
Overall, this study highlights the importance of understanding the genetic factors involved in pregnancy loss. Despite the increased risk it poses, the persistence of this variant in the population suggests that other factors may counterbalance its negative effects, thereby providing an intriguing avenue for further research.
For more information, refer to the research article published in Nature Structural & Molecular Biology: “Variant in the synaptonemal complex protein SYCE2 associates with pregnancy loss through effect on recombination” (DOI: 10.1038/s41594-023-01209-y).
FAQ: Genetics of Pregnancy Loss
1. What is the main finding of the study on the genetics of pregnancy loss?
– The study discovered a low-frequency missense variant in the SYCE2 gene that increases the risk of pregnancy loss by 22%.
2. What is the role of the SYCE2 gene?
– The SYCE2 gene is responsible for producing a protein complex that plays a crucial role in the alignment of homologous chromosomes during meiosis, the process of generating human egg and sperm cells.
3. What is the significance of recombination in relation to pregnancy loss?
– Recombination is an essential step in meiosis and allows for genetic diversity and proper alignment of chromosomes. The study found that the variant in the SYCE2 gene impacts the positioning of recombination events, potentially affecting successful pregnancies.
4. Does the study account for all types of pregnancy losses?
– The association with pregnancy loss in the study specifically focuses on losses that can be detected, potentially underestimating its overall effect on early gestational losses that occur before detection.
5. What does the persistence of the variant in the population suggest?
– Despite the increased risk it poses, the persistence of the variant in the population suggests that other factors may counterbalance its negative effects, which opens avenues for further research.
– Chromosomal abnormalities: Abnormalities or changes in the structure or number of chromosomes, which can lead to pregnancy loss or other health issues.
– Genome-wide association study: A study that explores the relationship between genetic variants across the entire genome and specific traits, diseases, or conditions.
– Missense variant: A genetic variant that causes a single amino acid change in the protein encoded by a gene.
– Homologous chromosomes: Chromosome pairs that contain the same genes but may have different versions (alleles) of those genes.
– Meiosis: The process of cell division that produces egg and sperm cells, involving the recombination and reduction of genetic material.
– Recombination: The process that shuffles and exchanges genetic material between homologous chromosomes during meiosis, leading to genetic diversity.
– deCODE genetics (official website for deCODE genetics, the subsidiary of Amgen mentioned in the article)
– Nature Structural & Molecular Biology (journal where the research article was published)