Learn about cystic fibrosis, a genetic disorder that affects the lungs, pancreas, and other organs, and how to treat and live with this chronic disease.
CF is a rare genetic disease found in about 30,000 people in the U.S. If you have CF or are considering testing for it, knowing about the role of genetics in CF can help you make informed decisions about your health care.
If you or your child has just been diagnosed with cystic fibrosis, or your doctor has recommended testing for CF, you may have many questions.
Diagnosing CF is a multistep process. A complete diagnostic evaluation should include a newborn screening, a sweat chloride test, a genetic or carrier test, and a clinical evaluation at a CF Foundation-accredited care center.
Raising a child with cystic fibrosis can bring up many questions because CF affects many aspects of your child’s life. Here you’ll find resources to help you manage your child’s daily needs and find the best possible CF care.
Living with cystic fibrosis comes with many challenges, including medical, social, and financial. By learning more about how you can manage your disease every day, you can ultimately help find a balance between your busy lifestyle and your CF care.
People with CF are living longer, healthier lives than ever before. As an adult with CF, you may reach key milestones you might not have considered. Planning for these life events requires careful thought as you make decisions that may impact your life.
People with cystic fibrosis are living longer and more fulfilling lives, thanks in part to specialized CF care and a range of treatment options.
Cystic Fibrosis Foundation-accredited care centers provide expert care and specialized disease management to people living with cystic fibrosis.
We provide funding for and accredit more than 120 care centers and 53 affiliate programs nationwide. The high quality of specialized care available throughout the care center network has led to the improved length and quality of life for people with CF.
The Cystic Fibrosis Foundation provides standard care guidelines based on the latest research, medical evidence, and consultation with experts on best practices.
As a clinician, you’re critical in helping people with CF maintain their quality of life. We’re committed to helping you partner with patients and their families by providing resources you can use to improve and continue to provide high-quality care.
As part of the Cystic Fibrosis Foundation's mission to help improve the lives of people living with cystic fibrosis, the PSDC initiative taps the CF community to inform key efforts to support the management of daily care.
Your cystic fibrosis care team includes a group of CF health care professionals who partner with you to provide specialized, comprehensive CF care.
Many people living with cystic fibrosis and their families face complicated issues related to getting the care they need. Cystic Fibrosis Foundation Compass makes sure that no one has to do it alone.
CF Foundation Compass is a service that helps people with CF and their families with navigating insurance options, connecting to legal information and experts, finding available financial resources, and tackling other life issues.
CF care team members are paramount in providing highly specialized care to people living with CF. CF Foundation Compass can help by serving as a strategic ally for care teams, so team members can focus on their patients’ care.
CF Foundation Compass can help you navigate insurance, financial, legal, and other issues you are facing. Use this online form to start your conversation with a Compass case manager today.
The Cystic Fibrosis Foundation is the world’s leader in the search for a cure for CF and supports a broad range of research initiatives to tackle the disease from all angles.
The CF Foundation offers a number of resources for learning about clinical trials and treatments that are being developed to improve the treatment of cystic fibrosis.
Our understanding of CF continues to evolve as scientists study what causes the disease and how it affects the body. These insights drive the development of new and better treatments and bring us one step closer to a cure.
Researchers, supported by the CF Foundation, have made tremendous advances to improve the health and quality of life of people with CF. We are committed to providing the tools and resources you need to continuously build upon this work.
To help standardize the diagnosis of both infants with positive newborn screening results and older patients with what may be cystic fibrosis symptoms, the Cystic Fibrosis Foundation worked with CF medical experts to develop guidelines on the steps leading to a confirmed diagnosis.
Farrell PM, White TB, Ren CL, et al. Diagnosis of Cystic Fibrosis: Consensus Guidelines from the Cystic Fibrosis Foundation. J Pediatr. 2017 Feb;181S:S4-S15.e1. doi: 10.1016/j.jpeds.2016.09.064.
The diagnosis of cystic fibrosis is based on clinical signs and symptoms consistent with the disease and objective evidence of cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction. As our understanding of CF pathophysiology has evolved, three factors have contributed to a need for refinement of formal diagnostic criteria.
First, the advent of universal newborn screening (NBS) has altered the initial diagnostic scenario for most new patients. Establishing a CF diagnosis for these, often asymptomatic, newborns requires confirmation of the NBS. Second, increased use of CFTR genetic testing and significant progress in our understanding of CFTR variants have allowed CFTR genetic testing to play a greater role in defining disease related to CFTR dysfunction. Finally, there has been increasing recognition of situations in which prior CF diagnostic criteria did not adequately give an answer to whether an individual has CF. The most common example occurs when an infant has a positive newborn screen but does not meet sweat chloride or genetic criteria to confirm the diagnosis.
In the U.S., these asymptomatic newborns were described as having CFTR-related metabolic syndrome (CRMS), whereas a European-led advisory group used the term CF Screen Positive, Inconclusive Diagnosis (CFSPID). Details concerning the diagnostic challenge of CRMS/CFSPID are covered in a separate guidelines statement. Another situation in which CFTR dysfunction contributes to a clinical syndrome without fulfilling the diagnostic criteria of CF is CFTR-related disorder (CFTR-RD).
The Cystic Fibrosis Foundation assembled a group of 32 CF diagnosis experts from 10 countries to revise prior diagnostic criteria with specific attention to the above challenges. The discussion generated specific consensus statements voted on by conference participants. The statements that met the threshold of 80 percent agreement were enacted. Those that did not meet the consensus threshold underwent iterative revision. The results were published as six articles in a supplementary issue of the Journal of Pediatrics.
Sweat chloride testing should be performed according to approved procedural guidelines published in established international protocols, such as the Clinical and Laboratory Standards Institute (CLSI) 2009 Guidelines.
Newborns with a positive CF newborn screen, to increase the likelihood of collecting an adequate sweat specimen, should have the test performed bilaterally and when the infant weighs >2 kg, and is at least 36 weeks of corrected gestational age.
Newborns greater than 36 weeks gestation and >2 kg body weight with a positive CF newborn screen, or positive prenatal genetic test, should have sweat chloride testing performed as soon as possible after 10 days of age, ideally by the end of the neonatal period (4 weeks of age).
In infants with presumptive CF identified through NBS, CF treatment should not be delayed while efforts to establish a CF diagnosis are initiated.
Sweat chloride analysis should be performed within a few hours of sweat collection, and the results and interpretations should be reported to clinicians and parents or patients as soon as possible and certainly on the same day.
In individuals presenting with a positive newborn screen, clinical features consistent with CF, or a positive family history, a diagnosis of CF can be made if the sweat chloride value is ≥60 mmol/L.
Individuals who are screen-positive and meet sweat chloride criteria for CF diagnosis should undergo CFTR genetic testing if the CFTR genotype was not available through the screening process or is incomplete.
In individuals with a positive newborn screen, a sweat chloride of <30 mmol/L indicates that CF is unlikely.
Individuals with clinical features that may be consistent with CF who have a sweat chloride less than 30 mmol/L indicates that CF is less likely. It may however be considered if evolving clinical criteria and/or CFTR genotyping support CF and not an alternative diagnosis.
Individuals presenting with a positive newborn screen, symptoms of CF, or a positive family history, and sweat chloride values in the intermediate range (30-59 mmol/L) on two separate occasions, may have CF. They should be considered for extended CFTR gene analysis and/or CFTR functional analysis.
The latest classifications identified in the CFTR2 project should be used to aid with CF diagnosis:
In individuals presenting with a positive newborn screen, symptoms of CF, or a positive family history, the identification of two CF-causing mutations (defined by CFTR2) is consistent with a diagnosis of CF. Sweat chloride testing is necessary, though, to confirm the diagnosis.
The absence of detection of two CF-causing CFTR mutations does not exclude a diagnosis of CF.
If further CF functional testing is needed (nasal potential difference [NPD] and intestinal current measurement [ICM]), it should be performed in a validated reference center with trained staff certified by the CF Foundation Therapeutics Development Network (TDN) or European Cystic Fibrosis Society Clinical Trial Network (CTN).
In individuals with a positive newborn screen but variable or uncharacterized CFTR mutations (less than two CF-causing mutations), the diagnosis of CF can be made by demonstrating CFTR dysfunction (a sweat chloride >60 mmol/L or CF-typical NPD or ICM).
The term CRMS is used in the U.S. for health care delivery purposes, and CFSPID is used in other countries, but these both describe an inconclusive diagnosis following NBS.
The term CRMS/CFSPID is reserved for screen-positive individuals without clinical features consistent with a diagnosis of CF.
The definition of CRMS/CFSPID is an infant with a positive NBS test for CF and either:
Children designated as CRMS/CFSPID should undergo at least one repeat sweat chloride test at CF centers with suitable expertise, such as an accredited CF center.
Children designated as CRMS/CFSPID should have a clinical evaluation performed by CF providers to identify the minority that may develop clinical symptoms.
Children designated as CRMS/CFSPID can be considered for extended CFTR gene analysis (sequencing and or deletion duplication testing), as well as CFTR functional analysis (NPD/ICM) testing to further define their likelihood of developing CF.
The decision to reclassify children designated as CRMS/CFSPID as CF is an integrated decision that should take into account functional assessment of CFTR (sweat chloride, and possibly NPD/ICM), CFTR genetic analysis, and clinical assessment by the CF clinicians caring for the patient.
Genetic counseling should be offered to families of individuals followed for CRMS/CFSPID, including a discussion of the risk in future pregnancies.
Research recommendation: Infants with a designation of CRMS/CFSPID (by definition) do not have clinical features consistent with a diagnosis of CF and further research is needed to determine the prognosis and best practices for frequency and duration of follow up.
For individuals presenting with CF symptoms, the same diagnostic criteria recommended for the screened population for sweat chloride testing, CFTR genetic analysis, and CFTR functional testing should be used to confirm a CF diagnosis.
The diagnosis of CFTR-related disorder has been defined as a monosymptomatic clinical entity (CBAVD/pancreatitis/bronchiectasis) associated with CFTR dysfunction that does not fulfill the diagnostic criteria for CF.
Clinicians should avoid the use of terms like classic/nonclassic CF, typical/atypical CF, delayed CF, since these terms have no harmonized definition and could be confusing for families or caregivers.
Relevant manuscripts published after the original guidelines are listed below. These manuscripts have not been reviewed or endorsed by the guidelines committee.
Claire Keating, M.D., (Columbia University); Sherstin T Lommatzsch, M.D., (National Jewish Health); and Patrick Sosnay, M.D., (Johns Hopkins University)
The guidelines were published in February 2017, they were reviewed in April 2019 and it was determined that no update is needed at this time.
Share this Page
Follow Us On
With more than 70 chapters and offices across the country, there are plenty of ways to get involved.
Cystic Fibrosis Foundation
4550 Montgomery Ave.
Suite 1100 N
Bethesda, MD 20814
800-344-4823 (toll free)
Sign up for our emails