CRTC2 rs10908557: What Your Genotype Means
The genetic variant rs10908557 is a single nucleotide polymorphism located within the CRTC2 gene. It has been identified in large-scale genomic studies as being associated with human reproductive behavior traits, specifically the age at which individuals have their first child.
What each genotype means
Typical reproductive behavior profile
This genotype represents the common reference state for this variant. Research indicates that this variant is associated with reproductive traits such as age at first birth, though the specific influence of this genotype is part of a complex, polygenic architecture. It is important to remember that reproductive outcomes are influenced by many environmental and social factors alongside genetics.
Carried by approximately 45-60% of individuals depending on ancestral background, as the G allele frequency varies globally.
Associated with reproductive timing
Carrying one copy of the G allele has been statistically associated with variations in reproductive timing, such as age at first birth, in large-scale genomic studies. This variant is in high linkage disequilibrium with other functional sites in the CRTC2 gene, which plays a role in cellular signaling and development. This association is based on population-level data and does not predict individual reproductive outcomes.
This heterozygous genotype is common, appearing in roughly 40-50% of many populations based on reported allele frequencies.
Associated with reproductive timing
Carrying two copies of the G allele is associated with the same reproductive behavior trends observed in large-scale GWAS, specifically regarding age at first birth. Because this variant is linked to gene expression and methylation changes in the CRTC2 gene, it may influence pathways involved in human development. These findings reflect statistical correlations across large groups and should not be used to infer personal reproductive potential.
This genotype is found in approximately 5-15% of individuals in many populations, though frequencies vary significantly by ancestry.
Understanding the Variant
The variant rs10908557 is a single nucleotide polymorphism (SNP) located on chromosome 1. In the human genome, it is classified as an intronic variant, meaning it sits within a non-coding region of the CRTC2 gene. While it does not directly alter the protein sequence of the gene, research indicates that this SNP is in high linkage disequilibrium with other variants in the region. This means that rs10908557 is often inherited alongside other nearby genetic changes, making it a useful marker for researchers studying the functional impact of this specific genomic neighborhood. Because it is a non-coding variant, its primary influence is thought to be regulatory, potentially affecting how the CRTC2 gene is turned on or off in different tissues throughout the body.
The Role of the CRTC2 Gene
The CRTC2 gene encodes the CREB-regulated transcription coactivator 2 protein. This protein acts as a molecular sensor that responds to cellular signals like calcium and cyclic AMP. When activated, it moves into the cell nucleus to help regulate the expression of various target genes. Because of this function, CRTC2 is involved in a wide range of biological processes, including glucose metabolism and cellular signaling. In the context of reproduction, research suggests that CRTC2 plays a role in ovarian granulosa cells, where it acts as a mediator in steroidogenesis. By influencing how cells respond to hormonal signals, the gene helps coordinate complex developmental and reproductive pathways. Understanding this gene is a focus of ongoing research into how genetic variation contributes to differences in fertility and reproductive timing.
Research and Reproductive Associations
Large-scale genome-wide association studies (GWAS) have linked rs10908557 to reproductive behaviors, most notably the age at first birth. These studies analyze the DNA of hundreds of thousands of individuals to find statistical correlations between specific genetic markers and complex traits. The evidence for this association is considered moderate, as reproductive behavior is a highly complex trait influenced by a combination of genetic, environmental, and social factors. Researchers have observed that this variant is associated with the expression levels of CRTC2 in various tissues, including blood and lymphoblasts. While the statistical link to reproductive timing is robust in large cohorts, it is important to note that this variant explains only a small fraction of the total variation in these traits. The biological mechanisms connecting this specific SNP to reproductive outcomes remain an active area of scientific investigation.
Population Frequency
The frequency of the G allele (the effect allele) for rs10908557 varies across different ancestral populations. According to data from the gnomAD database, the frequency of this allele generally ranges from approximately 22% to 39% depending on the population group. For example, it is observed at a frequency of about 22.8% in African/African-American populations and around 30.6% in non-Finnish European populations. These variations are common in human genetics and reflect the diverse evolutionary history of different groups. Because the variant is relatively common, it is considered a standard polymorphism rather than a rare mutation. These frequency statistics are based on large-scale sequencing projects and provide a snapshot of how common this genetic marker is globally.
Interpreting Your Genetic Information
If you have received information about your genotype for rs10908557, it is important to view it within the context of current scientific understanding. This variant is associated with complex, polygenic traits, meaning that thousands of other genetic and environmental factors also contribute to reproductive outcomes. Consequently, this single SNP cannot be used to predict individual reproductive behavior or fertility. Genetic associations identified in research studies are statistical averages across large populations and do not translate into personal medical advice or diagnostic predictions. If you have questions about your reproductive health or family planning, the most appropriate course of action is to consult with a qualified healthcare provider or a genetic counselor. They can provide personalized guidance based on your medical history and clinical needs, rather than relying on individual genetic markers.
How common is this variant?
The G allele frequency for rs10908557 ranges from approximately 22% to 39% across global populations, making it a common genetic variant.
Frequently asked questions
Does rs10908557 determine when I will have children?
No. Reproductive timing is a complex trait influenced by many genetic, social, and environmental factors. This variant is only one of many genetic markers associated with the trait and cannot predict individual outcomes.
Is rs10908557 a mutation that causes infertility?
No. This is a common genetic polymorphism, not a disease-causing mutation. While it is associated with reproductive behavior in large studies, it is not a diagnostic marker for infertility.
Can I use this information to change my health plan?
No. Genetic associations found in research studies are for educational purposes and do not provide actionable medical advice. Always consult with a healthcare professional regarding your reproductive health.
Why is this variant linked to CRTC2?
The variant is located within the CRTC2 gene region. Research shows it is associated with the expression levels of this gene, which plays a role in cellular signaling and metabolic processes.
Sources & further reading
Educational information only, last refreshed 10/29/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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