CACNA1A rs56391955: Eye-Corner Wrinkling & Skin Aging
The genetic variant rs56391955 is a single nucleotide polymorphism located in an intronic region of the CACNA1A gene on chromosome 19. Genome-wide association research has linked this variant to individual differences in outer-eye corner wrinkle formation, commonly referred to as crow's feet. While the statistical correlation is recognized, it represents a common physical trait rather than a direct cause of skin or neurological disease.
What each genotype means
| Genotype | What the research suggests | Reading |
|---|---|---|
| CC | Homozygous for the common major allele. In population association studies, this baseline genotype is correlated with typical, expected trajectories of outer-eye corner wrinkle formation. It indicates an average genetic background for this specific periorbital skin marker. | Informational |
| CT | Heterozygous carrier having one copy of the effect allele. Studies associate this genotype with a slight, statistically measurable variation in susceptibility to outer-eye corner wrinkling compared to the homozygous major genotype. The overall physical effect remains minor and strongly influenced by sun exposure and lifestyle. | Informational |
| TT | Homozygous for the minor allele. Individuals carrying two copies have shown a genome-wide significant association with increased outer-eye corner wrinkle depth or formation rate in studied cohorts. This represents a benign phenotypic trait rather than a pathological skin disorder. | Higher attention |
Genomic Location and the CACNA1A Gene
The single nucleotide polymorphism rs56391955 is situated on human chromosome 19 within an intronic region of the CACNA1A gene, as cataloged in dbSNP and Ensembl. The CACNA1A gene provides instructions for producing the alpha-1A subunit of voltage-gated P/Q-type calcium channels (CaV2.1), which are essential for controlling calcium entry into cells and facilitating neurotransmission in the central nervous system. Because rs56391955 is located within an intron—a non-protein-coding stretch of DNA—it does not directly alter the amino acid sequence of the calcium channel protein. Instead, variants in these non-coding segments often function as regulatory markers that may subtly modulate local gene transcription or act as genetic tags inherited alongside other functional polymorphisms nearby.
Association with Outer-Eye Wrinkle Formation
In genetic epidemiology, rs56391955 was identified in genome-wide association studies (GWAS) investigating human facial morphology and cutaneous aging phenotypes. Research identified this variant as a genome-wide significant susceptibility locus associated with the severity and progression of outer-eye corner wrinkling, frequently called crow's feet. Periorbital skin is notably thin and subject to repetitive mechanical stress from facial expressions, making it particularly sensitive to age-related changes in extracellular matrix composition, microvascular perfusion, and cellular calcium signaling. While the statistical evidence linking rs56391955 to variation in periorbital wrinkling reaches genome-wide significance, the overall effect size is modest, meaning that genotype explains only a small portion of the total variation in skin aging patterns.
Distinguishing Common Traits from Clinical Disorders
It is critical to distinguish common trait-associated single nucleotide polymorphisms like rs56391955 from rare, highly penetrant pathogenic variants in the CACNA1A gene. Highly disruptive mutations or trinucleotide repeat expansions in CACNA1A are clinically recognized causes of severe neurological conditions, such as episodic ataxia type 2 (EA2), familial hemiplegic migraine type 1 (FHM1), and spinocerebellar ataxia type 6 (SCA6). In contrast, rs56391955 is a standard non-pathogenic variant associated with a benign cosmetic trait. Carrying the minor allele for this polymorphism does not confer a clinical diagnosis of a neurological channelopathy or any known skin disorder, nor does it imply abnormal brain calcium channel functioning.
Environmental Context and Practical Application
Genetic markers associated with skin traits reflect underlying biological predispositions, but they operate within a broad framework of environmental and lifestyle factors. Periorbital wrinkle formation is heavily driven by ultraviolet (UV) radiation exposure, smoking, air quality, hydration, sleep hygiene, and lifelong expressive muscle movements. Knowing your rs56391955 genotype does not provide actionable medical directives, nor does it guarantee the early onset or absence of wrinkles. Evidence-based dermatological practices—such as applying broad-spectrum sunscreen, wearing protective sunglasses, using moisturizers, avoiding tobacco smoke, and consulting a board-certified dermatologist for personalized skin health—remain the primary determinants of skin health regardless of an individual's genetic profile.
How common is this variant?
The minor allele frequency for rs56391955 is approximately 0.20 (20%) in East Asian populations, while it is observed at substantially lower frequencies or remains rare among individuals of European and African ancestries.
Frequently asked questions
Does having the rs56391955 risk allele mean I will get premature wrinkles?
No. The variant is associated with a small statistical shift in susceptibility to periorbital wrinkling, not an absolute outcome. Wrinkle formation is a complex trait heavily influenced by sun exposure, smoking, genetics, and natural aging.
Is the rs56391955 variant related to neurological disorders like ataxia or migraines?
No. While rare mutations in the CACNA1A gene can cause episodic ataxia or familial hemiplegic migraine, rs56391955 is a common non-coding variant linked specifically to facial skin wrinkling traits, not neurological disease.
Can I prevent outer-eye wrinkles if I carry this genetic variant?
Yes. Proven preventative skin habits remain effective regardless of genetics. Applying broad-spectrum daily sunscreen, wearing UV-blocking sunglasses, staying hydrated, and avoiding smoking are primary strategies for protecting periorbital skin.
Why is the frequency of rs56391955 different across ethnic groups?
Allele frequencies naturally diverge over human history due to geographic isolation, population bottlenecks, and genetic drift. While the minor allele is found at approximately 20% in East Asian populations, it is much less common in other ancestral backgrounds.
Sources & further reading
Educational information only, last refreshed 9/7/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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