Acknowledgement of Cystic Fibrosis has not been added yet.

Cystic Fibrosis is one of the most common inherited disorders, especially among people of European descent, with a prevalence of about 1 in 3,200 live births in this population, though it occurs in all ethnic groups. In the United States, about 35,000 people live with CF, and around 1,000 new cases are diagnosed each year. The global undiagnosed CF population is estimated to be >57,000 people in 49 countries. Due to advancements in diagnostic screening, CF is now diagnosed more frequently, even in populations where it has historically been less common.

Name	Abbreviation
Cystic fibrosis of pancreas	Cystic fibrosis of pancreas
Fibrocystic disease of pancreas	Fibrocystic disease of pancreas
Mucoviscidosis	Mucoviscidosis

CF is caused by several different mutations in the gene encoding a chloride ion channel on epithelial cells lining the airways, GI tract, and other tissues, called the cystic fibrosis transmembrane conductance regulator (CFTR). Under normal circumstances, this ion channel protein regulates proper surface hydration through movement of chloride ions, which allows mucus to be cleared. There are five different classes of CFTR gene mutations affecting proper protein folding, expression, trafficking to the cell surface, and ion channel opening. The most common mutations result in protein misfolding, keeping it from being expressed on the cell surface. In the lungs, this ultimately results in airway obstruction and increased bacterial infections leading to progressive lung damage. In the pancreas, the buildup of mucus prevents the release of digestive enzymes that help the body absorb food and key nutrients, resulting in malnutrition and poor growth. In the liver, the thick mucus can block the bile duct, causing liver disease. CF is an autosomal recessive disorder, meaning a child must inherit a mutated copy of the CFTR gene from each parent to develop the disease (see RareShare Guide on Genetic Inheritance). However, as carrier parents are typically asymptomatic, they might not have a documented family history of the disease. 

CF affects multiple organ systems with varying severity but symptoms typically include:

• Chronic Respiratory Issues: Persistent coughing, wheezing and shortness of breath, and frequent lung infections such as bronchitis or pneumonia.

• Digestive Problems: Thick mucus blocks the ducts of the pancreas, preventing enzymes from reaching the intestines and resulting in poor nutrient absorption, frequent greasy stools, intestinal blockage, severe constipation, and malnutrition.

• Delayed Growth: Due to digestive malabsorption, children with CF may have difficulty gaining weight and growing at a typical rate.

• Other symptoms: Salty-tasting skin caused by higher-than-normal chloride levels in sweat, male infertility, delayed puberty, osteoporosis. 

Diagnosis of CF is based on clinical findings, family history, and diagnostic tests, particularly in cases with respiratory or digestive symptoms. Early diagnosis, often via newborn screening, enables timely intervention to manage symptoms and improve quality of life.

• Newborn Screening: Blood test measuring immunoreactive trypsinogen (IRT), a chemical (proenzyme) made by the pancreas. Newborn screening for CF has been universal in the U.S. since 2010.

• Sweat Test (primary diagnostic tool): Measures sweat chloride levels, elevated in individuals with CF. 

• Genetic Testing: Confirms CF by identifying mutations in the CFTR gene.

• Pulmonary Function Tests: Help evaluate lung function and assess disease progression over time.

• Sputum Culture: Identifies bacteria or fungi to diagnose and treat lung infections.

• Fecal Elastase Test: Measures pancreatic function, as CF commonly affects digestive enzyme production.

While there is no cure for CF, treatments focus on a comprehensive approach to manage symptoms and improve quality of life:

• Airway Clearance Therapy (ACT): Twice daily chest physiotherapy helps clear mucus from the lungs and is recommended for all patients with CF.

• Medications: CFTR modulators target specific mutations in the CFTR gene and help improve function (e.g., Trikafta, Orkambi, Kalydeco). Other medications include bronchodilators, mucolytics, and antibiotics to manage lung infections.

• Pancreatic Enzyme Replacement Therapy (PERT): Helps aid digestion and nutrient absorption.

• Fat-Soluble Vitamin Replacement Therapy and Nutritional Support: High-calorie, high-fat diets, along with vitamins and supplements, are essential to meet the metabolic needs of individuals with CF.

The prognosis for CF has improved dramatically in recent decades due to advances in treatment, particularly with the advent of CFTR modulators. In the 1950s, children with CF rarely survived to elementary school. Life expectancy now extends into the 40s and beyond for many individuals, although the disease still requires lifelong management and can impact quality of life. Prognosis varies depending on several factors, including the type of CFTR mutations (modulator therapies are specific for certain mutations), age at diagnosis, access to specialized care, and adherence to treatment. Lung complications remain a leading cause of morbidity and mortality, but with regular monitoring, aggressive infection control, and symptomatic treatment, many people with CF can achieve a higher quality of life and longer life expectancy.

For more resources and information, please visit the Cystic Fibrosis Foundation: https://www.cff.org/

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