CFTR rs755588842: Understanding This Rare Genetic Variant
The rs755588842 variant is a rare genetic change located within the CFTR gene. It is categorized as a pathogenic missense variant that may affect the function of the chloride channel protein, and it is sometimes included in expanded reproductive carrier screening panels.
What each genotype means
Typical CFTR function
This genotype represents the most common genetic sequence at this position in the CFTR gene. It is considered the reference sequence and is not associated with the pathogenic p.Arg347His change.
This is the most common genotype found in the vast majority of the global population.
Cystic fibrosis carrier status
This genotype indicates you carry one copy of the p.Arg347His variant, which is a known pathogenic mutation in the CFTR gene. Carriers typically do not have cystic fibrosis but may have an increased risk for certain CFTR-related conditions; please consult with a genetic counselor or clinician to discuss what this means for your health and family planning.
This genotype is rare, with the variant allele occurring at a global frequency of approximately 0.00004.
Potential cystic fibrosis risk
This genotype indicates you carry two copies of the p.Arg347His variant. Because this variant is associated with defective chloride conductance, individuals with this genotype may be at risk for cystic fibrosis or related clinical manifestations. Please discuss these results with a medical professional or clinical geneticist for appropriate diagnostic evaluation.
This genotype is extremely rare in the general population.
What is the rs755588842 Variant?
The rs755588842 variant is a specific single nucleotide polymorphism (SNP) found within the CFTR gene. In genetics, a missense variant occurs when a single change in the DNA sequence results in the substitution of one amino acid for another in the final protein product. Specifically, this variant is known as p.Arg347His, meaning the amino acid arginine is replaced by histidine at position 347 of the CFTR protein. Because this change occurs in the coding region of the gene, it has the potential to alter the structure or stability of the protein. Scientists track these variants to understand how they might impact biological processes, particularly those related to ion transport across cell membranes.
The Role of the CFTR Gene
The CFTR gene provides instructions for making the cystic fibrosis transmembrane conductance regulator protein. This protein functions as a channel that transports negatively charged chloride ions into and out of cells. This movement of ions is essential for maintaining the proper balance of salt and water on cell surfaces, which helps produce thin, free-flowing mucus in organs like the lungs, pancreas, and liver. When the CFTR protein is defective or missing, the transport of chloride ions is impaired. This can lead to the production of abnormally thick and sticky mucus, which can clog airways and ducts in various organs. Understanding the function of this gene is critical for researchers studying conditions where this ion transport process is disrupted.
Research and Clinical Evidence
Research into rs755588842 is currently limited, and its clinical impact is primarily discussed in the context of reproductive carrier screening. Because the CFTR gene is associated with cystic fibrosis—a condition inherited in an autosomal recessive pattern—identifying variants that affect protein function is important for prospective parents. The evidence for this specific variant suggests it may cause defective chloride conductance, which is why it is monitored in clinical settings. However, because it is a rare variant, the full spectrum of its clinical consequences is still being studied. It is important to note that the presence of a variant does not automatically result in a clinical diagnosis, and the significance of such findings should always be discussed with a qualified genetic counselor or medical professional.
Population Frequency
The rs755588842 variant is considered very rare in the general population. According to data from the Genome Aggregation Database (gnomAD), the global allele frequency for this variant is approximately 0.00004. This low frequency indicates that the variant is not commonly found across diverse ancestral groups. In genetic studies, variants with such low frequencies are often classified as rare, which can make it more challenging to gather large-scale data on their specific health associations. Because it is so uncommon, most individuals will not carry this specific genetic change, and its presence is typically identified only through targeted or expanded genetic screening panels.
What This Information Means for You
If you have received information about this variant through a genetic test, it is essential to understand that this is not a medical diagnosis. Genetic variants are common, and many do not cause health issues on their own. For recessive conditions like those associated with the CFTR gene, being a carrier typically means you have one copy of a variant, which often does not cause symptoms. However, this information is valuable for family planning and understanding your genetic background. You should not make any medical decisions based on this information alone. Always consult with a healthcare provider or a genetic counselor who can interpret these results in the context of your personal and family medical history.
How common is this variant?
The rs755588842 variant is extremely rare, with a global allele frequency of approximately 0.00004 in the gnomAD database.
Frequently asked questions
What is the CFTR gene?
The CFTR gene provides instructions for making a protein that acts as a channel for chloride ions. This process is vital for maintaining the balance of salt and water in the body's cells.
Is rs755588842 a cause of cystic fibrosis?
The variant is categorized as a pathogenic missense variant, meaning it has the potential to affect protein function. However, clinical significance depends on many factors, and you should discuss your specific results with a genetic counselor.
What does it mean to be a carrier?
Being a carrier for a recessive condition usually means you have one copy of a variant gene and one typical copy. Carriers typically do not show symptoms of the condition themselves.
Should I be worried if I have this variant?
Finding a variant does not mean you have a disease. Genetic testing results should always be reviewed by a healthcare professional who can explain what they mean for your specific health situation.
Sources & further reading
Educational information only, last refreshed 10/14/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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Severe pathogenic mutation (p.Gly542Ter) associated with cystic fibrosis.
Classic cystic fibrosis in-frame 3-bp deletion variant (p.Phe508del / deltaF508) causing misfolding and impaired chloride channel trafficking.
Pathogenic frameshift mutation (c.3659delC) in CFTR linked to cystic fibrosis.
Pathogenic nonsense variant (p.Gly542Ter / G542X) causing autosomal recessive cystic fibrosis when inherited in trans with another CFTR pathogenic allele.
Also known as p.Arg117His (R117H), this CFTR variant is associated with mild or atypical cystic fibrosis and congenital bilateral absence of the vas deferens, with clinical severity influenced by the poly-T tract background.
A CFTR mutation associated with cystic fibrosis and CFTR-related disorders.