SRD5A2 rs111033623: Understanding This Genetic Variant
The rs111033623 variant is a specific change within the SRD5A2 gene, which provides instructions for making an enzyme essential for male sexual development. This variant is associated with 5-alpha-reductase 2 deficiency, a condition that can lead to atypical development of external genitalia in 46,XY infants.
What each genotype means
Typical enzyme function
This genotype represents the most common sequence for this location in the SRD5A2 gene. Individuals with this profile are expected to have typical steroid 5-alpha reductase 2 enzyme activity, which is necessary for normal androgen processing and male sexual development.
This is the most common genotype observed across all global populations.
Carrier of variant
This genotype indicates that you carry one copy of the variant allele. Because SRD5A2 deficiency is an autosomal recessive condition, carriers typically do not exhibit the clinical features of the disorder, though they may pass the variant to their offspring.
This genotype is rare in the general population, as the variant allele is not common.
Potential enzyme deficiency
This genotype indicates that you carry two copies of the variant allele, which is associated with steroid 5-alpha reductase 2 deficiency. This condition can lead to reduced or absent enzyme activity, potentially resulting in 46,XY disorders of sex development and ambiguous genitalia at birth. Please discuss these findings with a medical geneticist or your healthcare provider for clinical context and appropriate follow-up.
This genotype is extremely rare in the general population.
What is the rs111033623 Variant?
The rs111033623 variant is a specific genetic alteration located within the SRD5A2 gene. In genetics, an rsID (reference SNP identification number) acts as a unique label for a specific location in the human genome where a variation may occur. This particular variant is classified as a missense mutation, meaning it causes a change in the DNA sequence that results in the production of an altered protein. Because the SRD5A2 gene is responsible for encoding the steroid 5-alpha-reductase 2 enzyme, changes at this site can potentially disrupt the enzyme's ability to function correctly. This variant is studied primarily in the context of reproductive health and development, as the enzyme it produces is critical for the conversion of testosterone into dihydrotestosterone (DHT), a more potent androgen required for the proper formation of male external genitalia during fetal development.
The Role of the SRD5A2 Gene
The SRD5A2 gene plays a vital role in the endocrine system by producing the 5-alpha-reductase type 2 enzyme. This enzyme is primarily active in the prostate, seminal vesicles, and the skin of the external genitalia. Its main function is to convert testosterone into dihydrotestosterone (DHT). While testosterone is responsible for the development of internal male reproductive structures, DHT is necessary for the development of external male genitalia, such as the penis and scrotum. When the SRD5A2 gene is affected by pathogenic variants, the body may not produce enough DHT. This deficiency can lead to a spectrum of clinical presentations known as 46,XY disorders of sex development (DSD). In these cases, individuals with a 46,XY chromosomal makeup may be born with ambiguous or female-typical external genitalia, despite having functional testes and internal male structures.
Research and Clinical Associations
Research into SRD5A2 variants has established a clear link between pathogenic mutations and 5-alpha-reductase 2 deficiency. The evidence for this association is considered strong in clinical genetics, as the loss of enzymatic function directly correlates with the observed developmental outcomes. Studies often utilize clinical scoring systems, such as the external masculinization score, to categorize the severity of the condition. It is important to note that there is significant variability in how this deficiency presents; even among individuals with the same genotype, the clinical features can differ widely. This suggests that other genetic factors or environmental influences may play a role in the final phenotype. Because this is an autosomal recessive condition, an individual typically needs to inherit two copies of a pathogenic variant—one from each parent—to manifest the deficiency. Clinical diagnosis is usually confirmed through a combination of hormonal testing, physical examination, and genetic sequencing.
Population Frequency and Inheritance
The rs111033623 variant is considered a rare genetic change. In the context of autosomal recessive disorders, the frequency of such variants is often higher in populations with higher rates of consanguinity, where there is a greater likelihood of inheriting two copies of a rare recessive allele. Because the variant is rare, it is not commonly found in the general population. Most individuals who carry a single copy of the variant (heterozygotes) are typically asymptomatic carriers and do not show signs of the deficiency. The condition only manifests when an individual is homozygous or compound heterozygous for pathogenic variants in the SRD5A2 gene. Because of its rarity, large-scale population databases like gnomAD are essential for researchers to estimate how often this variant appears across different ancestral groups, though data for specific rare variants can remain limited.
What You Can Do With This Information
Genetic information regarding variants like rs111033623 is primarily intended for clinical and research purposes. If you or a family member have received a report identifying this variant, it is important to understand that this is not a medical diagnosis. Genetic testing results should always be interpreted by a qualified healthcare professional, such as a clinical geneticist or a genetic counselor, who can place the findings in the context of your personal and family medical history. They can provide guidance on what the results mean for you or your family, discuss the implications of carrier status, and explain the potential for recurrence in future pregnancies. Never make medical decisions based solely on a genetic report without consulting a clinician. If you have questions about reproductive health or developmental concerns, a specialist in pediatric endocrinology or reproductive medicine is the most appropriate person to provide expert advice and support.
How common is this variant?
The rs111033623 variant is a rare autosomal recessive variant, meaning it is found at very low frequencies in the general population across most ancestries.
Frequently asked questions
What is 5-alpha-reductase 2 deficiency?
It is a condition that affects male sexual development. It occurs when the body cannot effectively convert testosterone to dihydrotestosterone, which is needed for the development of male external genitalia.
Is rs111033623 a diagnosis?
No, identifying a genetic variant is not a medical diagnosis. A diagnosis requires a clinical evaluation by a healthcare professional, including physical exams and hormonal testing.
Can I be a carrier of this variant?
Yes, if you have one copy of a pathogenic variant, you are considered a carrier. Carriers typically do not show symptoms of the condition but can pass the variant to their children.
How is this condition inherited?
This condition follows an autosomal recessive inheritance pattern. This means an affected individual must inherit a pathogenic variant from both parents.
Who should I talk to about these results?
You should discuss these results with a genetic counselor or a medical specialist, such as a pediatric endocrinologist. They can help interpret the findings in the context of your health.
Sources & further reading
Educational information only, last refreshed 9/23/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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