CYP21A2 rs1154510: Understanding Non-Classical CAH Associations
The rs1154510 variant, often referred to as V281L, is a specific genetic change located within the CYP21A2 gene. It is strongly associated with non-classical congenital adrenal hyperplasia, a condition that can affect the body's ability to produce cortisol.
What each genotype means
Typical genetic profile
This genotype represents the most common sequence found in the general population for this specific location. It is not associated with the genetic changes linked to congenital adrenal hyperplasia in the CYP21A2 gene.
This is the most common genotype observed across most global populations.
Likely benign variant carrier
This genotype indicates the presence of one copy of the G allele at this position. Current research and clinical databases generally classify this specific variation as benign, meaning it is not expected to cause the enzyme deficiency associated with congenital adrenal hyperplasia.
This genotype is found at varying frequencies depending on ancestral background but is generally considered a common variation.
Common variant profile
This genotype consists of two copies of the G allele. It is frequently observed in genomic studies and is not considered a pathogenic mutation for congenital adrenal hyperplasia.
This genotype is commonly reported in large-scale genomic sequencing projects.
Rare variant profile
This genotype represents a rare variation at this position. There is currently insufficient clinical evidence to suggest that this specific genotype is associated with any disease state or functional change in the CYP21A2 gene.
This genotype is very rare in the general population.
What is the rs1154510 Variant?
The rs1154510 variant is a single nucleotide polymorphism (SNP) located in the CYP21A2 gene on chromosome 6. In scientific literature, this specific change is frequently identified as V281L, referring to the substitution of the amino acid valine with leucine at position 281 of the protein. This gene is situated within the human leukocyte antigen (HLA) class III region, a complex area of the genome involved in immune function and steroidogenesis. Because this region is highly repetitive and contains a non-functional pseudogene, genetic analysis of this area can be technically challenging. The rs1154510 variant is one of many known mutations in this gene that can alter the function of the encoded enzyme, which is essential for the synthesis of key hormones in the adrenal glands.
The Role of the CYP21A2 Gene
The CYP21A2 gene provides instructions for making an enzyme called 21-hydroxylase. This enzyme is critical for the adrenal glands to produce cortisol, a hormone that helps the body respond to stress, maintain blood pressure, and regulate metabolism. When the CYP21A2 gene carries certain variants, the resulting 21-hydroxylase enzyme may have reduced activity or be completely non-functional. This deficiency can lead to a group of disorders known as congenital adrenal hyperplasia (CAH). While some mutations cause severe, classic forms of the condition that are typically identified at birth, other variants like rs1154510 are associated with the non-classical form. In non-classical CAH, the enzyme retains some function, which often leads to milder symptoms that may not appear until later in childhood or during adolescence.
Research and Clinical Evidence
The association between rs1154510 and non-classical congenital adrenal hyperplasia is well-documented in clinical genetics. Research indicates that this variant is a common cause of the non-classical form of the disorder, which is characterized by a partial deficiency of the 21-hydroxylase enzyme. The evidence for this association is considered strong, as the variant has been identified in numerous individuals presenting with symptoms related to impaired cortisol biosynthesis. It is important to note that the clinical presentation of CAH can vary significantly between individuals, even among those with the same genotype. This variability is often due to the complex nature of the CYP21A2 gene and the potential for other genetic or environmental factors to influence how the condition manifests. Clinicians use this information to help guide diagnostic testing and management strategies for patients.
Population Frequency and Distribution
The frequency of the rs1154510 variant varies significantly across different ethnic and ancestral populations. Studies have shown that this specific mutation is particularly prevalent in certain groups, such as Ashkenazi Jewish populations, where it has been reported at higher frequencies compared to other groups. Because CAH is an autosomal recessive condition, an individual typically needs to inherit two copies of a pathogenic variant—or be a compound heterozygote with two different variants—to exhibit symptoms. Understanding the prevalence of this variant in specific populations is a key component of genetic screening programs. Researchers continue to study these distribution patterns to better understand the global impact of CYP21A2 variants and to improve the accuracy of carrier screening and genetic counseling for families at risk.
Interpreting Your Genetic Information
Genetic information regarding variants like rs1154510 provides insight into your biological predispositions but does not constitute a medical diagnosis. If you have received results indicating you carry this variant, it is essential to understand that being a carrier does not necessarily mean you will develop a health condition. Because CAH is inherited in an autosomal recessive pattern, carriers are typically asymptomatic. However, if you are concerned about your health or family history, you should consult with a qualified healthcare provider or a genetic counselor. They can help interpret your results in the context of your overall health and provide guidance on whether further clinical testing is appropriate. Never make changes to your health management or medication based solely on genetic reports without professional medical advice.
How common is this variant?
The frequency of the rs1154510 (V281L) variant is highly variable by ancestry, with notably higher carrier frequencies observed in Ashkenazi Jewish populations compared to other ethnic groups.
Frequently asked questions
What is non-classical congenital adrenal hyperplasia?
Non-classical congenital adrenal hyperplasia is a milder form of a genetic disorder that affects the adrenal glands' ability to produce cortisol. It is caused by mutations in the CYP21A2 gene that result in a partially functional 21-hydroxylase enzyme.
Does having the rs1154510 variant mean I have CAH?
Not necessarily. Because CAH is an autosomal recessive condition, carrying one copy of the variant usually does not cause symptoms. A diagnosis requires a clinical evaluation by a doctor, often involving hormone testing.
Should I be tested for CYP21A2 mutations?
Genetic testing for CYP21A2 is typically recommended for individuals with symptoms of CAH or those with a family history of the condition. You should discuss the necessity of testing with a genetic counselor or your primary care physician.
Can this variant affect my response to medication?
The rs1154510 variant is primarily associated with the production of the 21-hydroxylase enzyme rather than drug metabolism. However, if you are taking medications for an adrenal condition, always discuss your dosing and management with your clinician or pharmacist.
Sources & further reading
Educational information only, last refreshed 9/16/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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Pathogenic variant (p.Val282Leu) in CYP21A2 associated with non-classic congenital adrenal hyperplasia.
Pathogenic variant associated with non-classic congenital adrenal hyperplasia presenting with hyperandrogenism, oligomenorrhea, and subfertility.
Pathogenic variant in CYP21A2 associated with 21-hydroxylase deficiency, used in reproductive carrier screening.
Pathogenic missense variant in CYP21A2 associated with 21-hydroxylase deficiency, a cause of congenital adrenal hyperplasia.
Well-characterized pathogenic missense variant (p.Pro30Leu) causing non-classic congenital adrenal hyperplasia and female hyperandrogenic subfertility.
This variant in the CYP21A2 gene is involved in steroid hormone metabolism and is noted in clinical databases.