CFTR rs74551128: Understanding Cystic Fibrosis Carrier Status
The genetic variant rs74551128 is located within the CFTR gene and is associated with carrier status for cystic fibrosis. While not causing the condition itself, understanding this variant is important for genetic inheritance and family planning.
What each genotype means
Typical CFTR function
This genotype represents the common, ancestral form of this position in the CFTR gene. Individuals with this genotype do not carry the A455E mutation at this location.
This is the most common genotype observed in the general population.
Cystic fibrosis carrier status
This genotype indicates you carry one copy of the CFTR p.Ala455Glu mutation. This variant is recognized as pathogenic and is associated with cystic fibrosis; if you have concerns about your health or family planning, please discuss this result with a genetic counselor or clinician.
This is a rare genotype, identified in individuals of various backgrounds, including those of French-Canadian ancestry.
Potential cystic fibrosis-related condition
This genotype indicates you carry two copies of the CFTR p.Ala455Glu mutation. Research indicates this variant impairs CFTR protein function, and you should discuss the clinical implications of this finding with a healthcare professional or specialist.
This genotype is extremely rare in the general population.
The CFTR Gene and rs74551128
Rs74551128 is a specific variation, known as a single nucleotide polymorphism (SNP), found within the CFTR gene. The CFTR gene, which stands for Cystic Fibrosis Transmembrane conductance Regulator, is crucial for producing a protein that functions as a channel across cell membranes. This channel is vital for regulating the movement of salt and water in and out of cells, which is essential for maintaining the normal consistency of mucus and other secretions in various organs like the lungs, pancreas, and intestines. When the CFTR protein doesn't function correctly due to genetic mutations, it can lead to the buildup of thick, sticky mucus, a hallmark of cystic fibrosis. The variant rs74551128 represents a specific change at a particular location within this important gene.
Association with Cystic Fibrosis Carrier Status
Research has identified rs74551128, also referred to as p.Ala455Glu at the protein level, as a variant linked to cystic fibrosis (CF) carrier status. Individuals who are carriers possess one altered copy of the CFTR gene and one typical copy. They generally do not exhibit symptoms of CF but can pass the altered gene to their offspring. The evidence strength for this association is classified as moderate, indicating a recognized link supported by scientific studies, though further research may refine our understanding. It is important to distinguish between being a carrier and having cystic fibrosis; carriers are healthy but can contribute to the inheritance of CF.
Understanding Genetic Inheritance of CFTR Variants
Cystic fibrosis is an autosomal recessive disorder, meaning that a person must inherit two altered copies of the CFTR gene, one from each parent, to develop the condition. If an individual inherits only one altered copy, they become a carrier. Carriers typically lead normal lives without symptoms but have a chance of passing the altered gene to their children. When both parents are carriers of a CFTR mutation, each child has a 25% chance of inheriting two altered copies and developing CF, a 50% chance of being a carrier, and a 25% chance of inheriting two typical copies. Understanding carrier status for variants like rs74551128 is a key aspect of genetic counseling and family planning.
Population Frequency of rs74551128
The variant rs74551128 is characterized as rare within the general population. Its frequency can differ across various ancestral groups, with lower occurrences generally observed. Due to its rarity, comprehensive data on the specific frequencies of its genotypes across all populations is not as extensively documented as for more common genetic variations. This rarity underscores the importance of consulting detailed genetic testing reports and seeking guidance from genetic counselors for personalized information regarding the prevalence and potential implications of this variant within one's specific ancestry.
Interpreting Your Genetic Information
Information about genetic variants like rs74551128 is provided for educational purposes and should not be used for self-diagnosis or to make medical treatment decisions. While this variant is associated with cystic fibrosis carrier status, genetic test results are most meaningful when interpreted by a qualified healthcare professional, such as a genetic counselor. They can consider your personal health history, family history, and other relevant factors to explain the implications of your results. Genetic information is one part of a comprehensive health assessment, and professional guidance is essential for understanding its impact and determining any necessary next steps.
How common is this variant?
Rs74551128 is considered a rare variant. Its frequency can vary across different ancestral populations, with lower occurrences generally observed.
Frequently asked questions
What is rs74551128 and what gene is it in?
Rs74551128 is a specific genetic variation, or SNP, located within the CFTR gene. The CFTR gene provides instructions for making a protein that regulates salt and water transport in cells, and variants in this gene are linked to cystic fibrosis.
Does rs74551128 cause cystic fibrosis?
No, rs74551128 itself does not cause cystic fibrosis. It is associated with carrier status, meaning an individual has one altered copy of the CFTR gene. Cystic fibrosis occurs when a person inherits two altered copies of the CFTR gene.
How common is the rs74551128 variant?
Rs74551128 is classified as a rare variant. Its presence is not frequent in the general population, and its occurrence can differ among various ancestral groups.
What does it mean to be a carrier for cystic fibrosis?
Being a carrier means you have one altered copy of the CFTR gene and one typical copy. Carriers usually do not show symptoms of cystic fibrosis but can pass the altered gene to their children.
Should I get tested for rs74551128?
Testing for rs74551128 is often part of broader CFTR gene carrier screening. Discuss with your healthcare provider or a genetic counselor if testing is appropriate for you, based on your personal and family health history.
Where can I find more information about the CFTR gene?
Reliable sources for more information include MedlinePlus Genetics, the Cystic Fibrosis Foundation website, and scientific literature databases like PubMed, which provide detailed information on the CFTR gene and related conditions.
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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