SPATA16 rs138356441: Understanding This Rare Genetic Variant
The rs138356441 variant is a rare genetic change located within the SPATA16 gene. It has been studied for its potential role in male infertility, specifically in relation to a condition called globozoospermia, where sperm lack a properly formed acrosome.
What each genotype means
Typical SPATA16 genotype
This is the most common genotype for this location in the SPATA16 gene. It is considered the baseline or reference sequence in the general population.
Carried by the vast majority of individuals in all global populations.
Carrier of rare variant
You carry one copy of the rare A allele. Research indicates that homozygous mutations in SPATA16 are associated with globozoospermia, a condition affecting sperm morphology and fertility, but carrying a single copy is generally not associated with this clinical presentation.
This genotype is extremely rare, found in fewer than 1 in 20,000 individuals globally.
Potential fertility risk
You carry two copies of the rare A allele. Published research links homozygous variants in SPATA16 to globozoospermia, which can cause round-headed sperm and fertilization failure. If you are experiencing concerns regarding fertility, please discuss these findings with a reproductive specialist or genetic counselor.
This genotype is exceptionally rare and has not been observed at significant frequencies in major population databases.
What is the rs138356441 Variant?
The rs138356441 variant is a specific change in the DNA sequence of the SPATA16 gene. In genetics, a variant like this is often referred to as a single nucleotide polymorphism (SNP) or a point mutation, depending on its frequency and impact. This particular variant is classified as a missense change, meaning it alters the genetic code in a way that results in a different amino acid being incorporated into the protein produced by the gene. Because the SPATA16 gene is highly specialized for function within the male reproductive system, changes in its sequence are of significant interest to researchers studying the molecular basis of spermatogenesis. This variant is cataloged in major genomic databases, which allow scientists to track its presence across different human populations and investigate its potential biological consequences.
The Role of the SPATA16 Gene
The SPATA16 gene, which stands for Spermatogenesis Associated 16, plays a critical role in the development of healthy sperm. Specifically, it is involved in the formation of the acrosome, a specialized cap-like structure located at the tip of the sperm head. The acrosome contains enzymes that are essential for the sperm to penetrate the outer layer of an egg during fertilization. Research indicates that the protein encoded by SPATA16 localizes to the Golgi apparatus and proacrosomal vesicles, which are the cellular machinery responsible for building the acrosome. When this gene is functioning correctly, it ensures that the acrosome is properly formed and positioned. Disruptions in this process can lead to structural abnormalities in the sperm, which may impair their ability to fertilize an egg.
Research and Clinical Associations
Scientific research has linked mutations in the SPATA16 gene to a rare condition known as globozoospermia, or round-headed sperm syndrome. In this condition, sperm lack the acrosome entirely, resulting in a rounded head shape and significant fertility challenges. While some specific mutations in SPATA16 have been identified as causative in familial cases of globozoospermia, the evidence strength for many individual variants, including rs138356441, remains limited. It is important to note that globozoospermia is a complex condition that can be caused by mutations in several different genes, such as DPY19L2 and PICK1. Because the evidence for rs138356441 is not yet definitive, researchers continue to investigate how this specific variant might contribute to or interact with other factors in the development of male infertility.
Understanding Your Results
If you encounter information about this variant, it is important to understand that genetic data is only one piece of a much larger biological puzzle. This variant is extremely rare, and its presence does not automatically imply a diagnosis of any condition. Genetic testing results should always be interpreted by a qualified healthcare professional, such as a genetic counselor or a reproductive specialist, who can place the findings in the context of your overall health and family history. You cannot use this information to diagnose yourself or to make medical decisions. If you have concerns about fertility or reproductive health, the most appropriate step is to consult with a clinician who can provide personalized guidance, perform necessary clinical evaluations, and discuss the implications of any genetic findings in a supportive and accurate manner.
How common is this variant?
The rs138356441 variant is very rare in global human populations, with an allele frequency reported as less than 0.00005 in the gnomAD database.
Frequently asked questions
What is globozoospermia?
Globozoospermia is a rare form of male infertility characterized by sperm that have round heads and lack an acrosome. Because the acrosome is necessary for fertilization, this condition often leads to significant challenges in achieving pregnancy.
Is SPATA16 the only cause of globozoospermia?
No, globozoospermia is genetically heterogeneous, meaning it can be caused by mutations in several different genes. While SPATA16 is one known cause, other genes like DPY19L2 and PICK1 are also associated with the condition.
Should I be worried if I have this variant?
The presence of a rare variant does not necessarily mean you have a medical condition. You should discuss any genetic findings with a healthcare provider or a genetic counselor who can help you understand what the results mean for your specific situation.
Can I fix a mutation in the SPATA16 gene?
Currently, there are no clinical treatments to 'fix' or edit genetic variants in the SPATA16 gene. Medical management for infertility focuses on assisted reproductive technologies, which should be discussed with a fertility specialist.
Sources & further reading
Educational information only, last refreshed 10/17/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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Loss-of-function variant in SPATA16 causing globozoospermia and male infertility.
Homozygous mutations in SPATA16 are a known cause of spermatogenic failure type 6 (SPGF6), characterized by globozoospermia and male infertility due to acrosome formation defects.