CFTR Gene and Cystic Fibrosis: Mutations and Clinical Trials

The CFTR gene sits on chromosome 7q31.2, and its full name is CF transmembrane conductance regulator. Orphanet links CFTR to 6 rare conditions and lists variants in the gene as a cause of 2 of them. Trial Friend's Cystic Fibrosis page lists CFTR among the genes behind the condition. As of September 29, 2026, 21 recruiting or soon-opening trials on ClinicalTrials.gov name CFTR as a gene.

Other symbols for CFTR in gene databases: ABC35, MRP7, TNR-CFTR, dJ760C5.1.

See the trialsSearch another gene

What the CFTR gene does

CFTR makes a channel that moves chloride in and out of the cells that produce mucus, sweat, saliva, tears and digestive enzymes. That flow of chloride helps keep mucus thin and slippery.

Summarized from the CFTR page on MedlinePlus Genetics, U.S. National Library of Medicine, checked September 29, 2026.

CFTR and Cystic Fibrosis

These condition pages list CFTR among the genes behind the condition, checked against genetics references when each page was written.

Cystic Fibrosis

The condition usually appears only when both copies of the gene carry a disease-causing variant. One variant alone usually means a person is a carrier.

Biallelic CFTR variants cause CF; the specific variants determine eligibility for CFTR modulator drugs.

CFTR mutation clinical trials

These recruiting or soon-opening trials mention CFTR as a gene in their title, summary, eligibility rules or keywords. Some want people with a variant in it, and others study it more broadly, which is why each trial's own words are shown. In cancer trials the gene change is usually one found in the tumor rather than one a person inherited.

21 trials, checked September 29, 2026. The list refreshes from ClinicalTrials.gov every few hours.

RecruitingPhase 2NCT05248230
4D-710 in Adult Patients With Cystic Fibrosis
Cystic Fibrosis Lung
Why it's listed: “Bi-allelic mutations in the CFTR gene, or”
RecruitingNCT04732910
Modulate-CF: Cystic Fibrosis Transmembrane Regulator (CFTR) Biomarker Study to Evaluate the Rescue of Mutant CFTR in Patients With Cystic Fibrosis Treated With CFTR-modulators
Cystic Fibrosis
Why it's listed: Lists CFTR among its conditions or keywords
RecruitingPhase 4NCT07148739
Ensuring Access to Optimal Therapy in CF: The ENACT Study
Cystic Fibrosis (CF)
Why it's listed: “documentation of CF diagnosis per CFF diagnostic criteria and known CFTR genotype”
RecruitingNCT07303621
Population Pharmacokinetics of Elexacaftor-tezacaftor-ivacaftor in a Paediatric Population
Cystic Fibrosis (CF)
Why it's listed: “Cystic fibrosis is a rare, progressive genetic disease caused by a mutation in the CFTR (cystic fibrosis transmembrane conductance regulator) gene. Respiratory and nutritional e…”
RecruitingPhase 2NCT06747858
Safety, Tolerability and Efficacy Study of ARCT-032 in People With Cystic Fibrosis
Cystic Fibrosis · CFTR Gene Mutation
Why it's listed: Lists CFTR among its conditions or keywords
RecruitingNCT01851694
Beta-cell Response to Incretin Hormones in Cystic Fibrosis
Cystic Fibrosis · Pancreatic Insufficiency
Why it's listed: “Confirmed diagnosis of cystic fibrosis, defined by positive sweat test or CFTR mutation analysis according to CFF diagnostic criteria,”
RecruitingNCT05818319
Cystic Fibrosis in the Kidney: Monitoring the Effectiveness of Elexacaftor/tezacaftor/ivacaftor in Urine After a Short Pause of Therapy
Cystic Fibrosis (CF) · CFTR Gene Mutation
Why it's listed: Lists CFTR among its conditions or keywords
RecruitingPhase 2NCT07695090
Lumacaftor Yields Reversal of Impaired Cerebral Blood Flow in Heart Failure Patients
Heart Failure With Reduced Ejection Fraction
Why it's listed: Lists CFTR among its conditions or keywords
RecruitingEarly Phase 1NCT03587961
Personalized Theratyping Trial
Cystic Fibrosis
Why it's listed: “…plore the use of off-label CFTR modulators that may affect CFTR function in patients with CFTR mutations that are not currently approved for these drugs.”
RecruitingNCT03670472
Correction of Nonsense Mutations in Cystic Fibrosis
Cystic Fibrosis
Why it's listed: “…ut also to propose therapeutic approaches for the correction of nonsense mutations of the CFTR gene in cystic fibrosis in a targeted way for a patient.”
RecruitingNCT06191640
Sinus Disease in Young Children With Cystic Fibrosis
Cystic Fibrosis in Children · Cystic Fibrosis · Chronic Rhinosinusitis (Diagnosis)
Why it's listed: “CFTR mutation consistent with FDA labeled indication of highly effective modulator therapy (ivacaftor o…”
RecruitingPhase 1NCT05504837
A Study Assessing KB407 for the Treatment of Cystic Fibrosis
Cystic Fibrosis
Why it's listed: “Two copies of a disease causing mutation in the CFTR gene”
RecruitingNCT03052283
Development and Validation of a Disease Specific PROM to Assess Abdominal Involvement in Patients With CF (CFAbd-Score)
Cystic Fibrosis
Why it's listed: “detection of 2 disease causing CFTR mutations with evidence of organ involvement.”
RecruitingNCT06504589
A Research Study to Advance the CF Therapeutics Pipeline for People Without Modulators
Cystic Fibrosis
Why it's listed: “Two well-characterized disease-causing pathogenic variants in the CFTR gene”
RecruitingNCT03161808
Rare CFTR Mutation Cell Collection Protocol (RARE)
Cystic Fibrosis
Why it's listed: “…ve CFTR are being evaluated in important clinical trials, but most target the most common CFTR mutation F508del. Many patients with rare CF mutations are not able to participate in those studie…”
RecruitingNCT04580368
Testing Drug Efficacy in Cystic Fibrosis Through N-of-1 Trials
Cystic Fibrosis
Why it's listed: “At least one rare CFTR variant (incidence of \<5% of the CF population)”
RecruitingNCT04509050
Study to Evaluate Biological & Clinical Effects of Significantly Corrected CFTR Function in Infants & Young Children
Cystic Fibrosis
Why it's listed: “CFTR mutations consistent with FDA labeled indication of highly effective modulator therapy (ivacaftor o…”
RecruitingNCT07192679
MAGNIFY - Pulmonary Magnetic Resonance Imaging for Cystic Fibrosis
Cystic Fibrosis (CF)
Why it's listed: “A confirmed clinical diagnosis of CF, consisting of 2 confirmed disease-causing CFTR mutations along with either positive sweat chloride (\>60mmol/L, measured before starting CFTR modu…”
RecruitingNCT06284577
Quality of Life and Gut Health in Pediatric Patients With Cystic Fibrosis
Cystic Fibrosis in Children
Why it's listed: “CFTR mutations eligible for treatment with ETI”
RecruitingNCT06045702
Establishment of a Primary Epididymal Cell Model From Epididymal Samples to Study CFTR Gene Regulation
Cystic Fibrosis · Congenital Bilateral Absence of Vas Deferens · Sterility, Male
Why it's listed: “…study is to better understand the role and involvement of the regulatory elements of the CFTR gene, with the aim of better describing the 3D organisation of chromatin at the CFTR locus in…”
Opening soonNCT07402434
A Prospective Study of Advanced Diagnostics in People With an Unclear Diagnosis of Cystic Fibrosis
Cystic Fibrosis (CF) · CFTR-related Disorders
Why it's listed: “…st line CFTR testing (individuals who do not fulfil CF diagnostic criteria \[2 CF-causing CFTR variants and/or sweat chloride concentration ≥60 mmol/L\]). Of note, there are some individuals wi…”

All conditions linked to CFTR gene mutations

Orphanet records how each gene relates to each condition. Orphanet links CFTR to 6 rare conditions and lists variants in the gene as a cause of 2 of them.

  • Causes it. Disease-causing variants in this gene are a direct cause of the condition.
  • Raises risk. Some variants raise the chance of the condition without guaranteeing it.
  • Being studied. Researchers suspect a role that isn't confirmed yet.
Cystic fibrosisCauses itTrial Friend pageOrphanet
Congenital bilateral absence of vas deferensCauses itOrphanet
Male infertility with azoospermia or oligozoospermia due to single gene mutationRaises riskOrphanet
Aquagenic palmoplantar keratodermaBeing studiedOrphanet
Autosomal recessive hereditary chronic pancreatitisBeing studiedOrphanet
Idiopathic bronchiectasisBeing studiedOrphanet

CFTR genetic test results and what a variant can mean

Labs sort each variant they find into 5 groups, from pathogenic and likely pathogenic through uncertain significance to likely benign and benign. Only the first 2 are usually treated as the cause of a condition. A variant of uncertain significance, or VUS, is one without enough evidence either way yet, and labs can reclassify it as research builds.

A genetic counselor or your doctor can explain what a specific result means for you and your family. Our genetic testing guide covers the terms, and MedlinePlus Genetics from the National Library of Medicine has a plain-language page on CFTR.

CFTR gene questions

What does the CFTR gene do?

CFTR makes a channel that moves chloride in and out of the cells that produce mucus, sweat, saliva, tears and digestive enzymes. That flow of chloride helps keep mucus thin and slippery. This summary follows MedlinePlus Genetics from the U.S. National Library of Medicine.

Are there clinical trials for people with CFTR gene variants?

As of September 29, 2026, 21 recruiting or soon-opening trials on ClinicalTrials.gov name CFTR as a gene. Each one is listed on this page with the words from the trial that mention the gene. ClinicalTrials.gov also lists 180 open trials for Cystic Fibrosis, and Match Me on Trial Friend can check those against age, sex, location and treatment history.

What conditions are linked to the CFTR gene?

Orphanet links CFTR to 6 rare conditions and lists variants in the gene as a cause of 2 of them. They include Cystic fibrosis, Congenital bilateral absence of vas deferens, Male infertility with azoospermia or oligozoospermia due to single gene mutation, Aquagenic palmoplantar keratoderma, Autosomal recessive hereditary chronic pancreatitis and Idiopathic bronchiectasis. Orphanet is the European rare disease database run by INSERM in Paris.

How is Cystic Fibrosis inherited?

The inheritance pattern is autosomal recessive. The condition usually appears only when both copies of the gene carry a disease-causing variant. One variant alone usually means a person is a carrier. Biallelic CFTR variants cause CF; the specific variants determine eligibility for CFTR modulator drugs.

What does a CFTR variant of uncertain significance mean?

A variant of uncertain significance, or VUS, is a change in the gene that labs don't yet have enough evidence to call disease-causing or harmless. It is not used on its own to diagnose a condition, and labs can reclassify it as research builds. A genetic counselor can explain what a specific result means for you and your family.

Sources

  • Gene and condition links from Orphadata (Orphanet, INSERM US14), used under CC BY 4.0, read September 29, 2026.
  • Trials from ClinicalTrials.gov, read September 29, 2026.
  • CFTR gene, MedlinePlus Genetics, U.S. National Library of Medicine.
  • Inheritance and gene notes from the Trial Friend condition pages above, each checked against genetics references.

Other gene pages

The gene search covers every gene Orphanet links to a rare disease.