Why is cystic fibrosis (CF) so common?
Cystic fibrosis (CF) is the most common fatal genetic disorder of caucasians. While it has been hypothesized that there is a CF heterozygote advantage which allowed the gene to achieve such high prevalence, the nature of that advantage remains a mystery. The recent identification and sequencing of t …
What is the evolutionary advantage of cystic fibrosis?
In the case of cystic fibrosis, the evolutionary advantage it confers is still a matter of debate. One theory is that it may give resistance to cholera or other illnesses that cause diarrhea and dehydration. The logic of this theory is that the altered salt and water balance may protect against dehydration during bouts of severe diarrhea.
Is aerobic exercise good for cystic fibrosis?
Usually, aerobic exercise is considered a supplement to other airway clearance techniques; however, in a small proportion of adults with CF ages 20-40, exercise is their primary airway clearance method. People with cystic fibrosis should never substitute exercise for airway clearance techniques without consulting their medical team. 5
Why do people with cystic fibrosis need extra calories and nutrients?
People with CF need extra calories and nutrients to help them fight infection and keep their lungs strong, particularly if they get sick with colds or the flu. This opens in a new window.
What are 3 interesting facts about cystic fibrosis?
About 30,000 people in the US suffer from CF. Cystic fibrosis is one of the most common lung diseases in children. Cystic fibrosis is an autosomal recessive genetic disorder – passed down through families. CF is generally diagnosed in infants but mild forms of the disease can sometimes be diagnosed in adults.
How do people with cystic fibrosis live a healthy life?
Daily Life with Cystic Fibrosis: Nutrition and Exercise The main lifestyle recommendations from the National Institutes of Health (NIH) include: not smoking and avoiding tobacco smoke, washing hands often to lower risk of infection, exercising regularly and drinking lots of fluids, and doing chest physical therapy.
What is the heterozygote advantage of cystic fibrosis?
It is suggested that cystic fibrosis heterozygotes withstand secretory diarrhoea better than normal individuals and so are genetically advantaged. This hypothesis has been examined by measuring electrogenic chloride secretion in gut epithelia of normal and heterozygous CF mice.
Can people with cystic fibrosis get better?
These secreted fluids are normally thin and slippery. But in people with CF, they're thick and sticky. Instead of acting as lubricants, these secretions plug up the tubes, ducts and airways in your body. Although there is no cure for cystic fibrosis, people with this condition are generally able to live normal lives.
Why are people with cystic fibrosis living longer?
Cystic fibrosis tends to get worse over time and can be fatal if it leads to a serious infection or the lungs stop working properly. But people with cystic fibrosis are now living for longer because of advancements in treatment. Currently, about half of people with cystic fibrosis will live past the age of 40.
What celebrities have cystic fibrosis?
Some patients suffering from CF are celebrities or became celebrities due to their fight against the disease.Alexandra Deford. ... Alice Martineau. ... Andrew Simmons. ... Bob Flanagan. ... Fredric Chopin. ... Gregory Lemarchal. ... Gunnar Esiason. ... Celine Dion's niece Karine.More items...•
What are the benefits of early diagnosis of cystic fibrosis?
Diagnosing CF Early Is Important This can help delay or prevent serious, lifelong health problems related to CF. Research shows that children who receive CF care early in life have better nutrition and are healthier than those who are diagnosed later.
Is cystic fibrosis good for gene therapy?
Gene therapy has shown significant promise not just for people living with cystic fibrosis, but for other genetic diseases.
Why is cystic fibrosis a good candidate for gene therapy?
Gene therapy is particularly attractive for diseases that currently do not have satisfactory treatment options and probably easier for monogenic disorders than for complex diseases. Cystic fibrosis (CF) fulfills these criteria and is therefore a good candidate for gene therapy-based treatment.
What is it like living with CF?
Mucus buildup leads to complications ranging from mild or inconvenient to detrimental. The digestive system and lungs are the two systems CF hits the hardest. It can cause difficulty processing food, but the worst consequence of mucus buildup is the infections that can stem from it. CF is a cyclical journey.
What is the longest someone has lived with cystic fibrosis?
The oldest person in the United States diagnosed with CF for the first time was 82. Those who are not diagnosed with CF until later in life generally suffer from colds, sinus infections, pneumonia, stomach pains, and acid reflux. They may also have trouble gaining or keeping on weight.
Can you live long with CF?
While there is no cure yet for cystic fibrosis (CF), people with CF are living longer, healthier lives than ever before. In fact, babies born with CF today are expected to live into their mid-40s and beyond. Life expectancy has improved so dramatically that there are now more adults with cystic fibrosis than children.
What is the heterozygote advantage linked to the high frequency of the cystic fibrosis allele in Caucasians?
Three firm conclusions are reached; the first is that the most influential factor in causing the high CF prevalence amongst peoples in European ancestry is heterozygote advantage to Tuberculosis.
What is heterozygous for cystic fibrosis?
Patients heterozygous for mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene may be more susceptible to respiratory infections than the general population.
What is an example of a heterozygote advantage?
Heterozygous advantage is one of several controversial explanations for the existance of genetic variability in natural populations. The classic example of heterozygous advantage is sickle cell anemia where humans who are homozygotic for sickle shaped cells (pictured opposite) suffer from a near lethal condition.
Is there a heterozygote advantage to genetic disorders?
Heterozygote Advantage Examples In traits subject to heterozygote advantage, heterozygotes will have a higher survival rate and fitness despite carrying a disease-causing allele because their dominant allele protects them from the genetic disease, while their recessive allele protects them from an infectious disease.
What are the symptoms of cystic fibrosis?
People who are not diagnosed until adulthood usually have milder disease and are more likely to have atypical symptoms, such as recurring bouts of an inflamed pancreas (pancreatitis), infertility and recurring pneumonia. People with cystic fibrosis have a higher than normal level of salt in their sweat.
Why are men with cystic fibrosis infertile?
Almost all men with cystic fibrosis are infertile because the tube that connects the testes and prostate gland (vas deferens) is either blocked with mucus or missing entirely. Certain fertility treatments and surgical procedures sometimes make it possible for men with CF to become biological fathers.
Why do cystic fibrosis patients have dehydration?
Electrolyte imbalances and dehydration. Because people with cystic fibrosis have saltier sweat, the balance of minerals in their blood may be upset. This makes them prone to dehydration, especially with exercise or in hot weather.
What is the mutation in the cystic fibrosis transmembrane conductance regulator?
In cystic fibrosis, a defect (mutation) in a gene — the cystic fibrosis transmembrane conductance regulator (CFTR) gene — changes a protein that regulates the movement of salt in and out of cells. The result is thick, sticky mucus in the respiratory, digestive and reproductive systems, as well as increased salt in sweat.
Why is it so hard to breathe in cystic fibrosis?
In cystic fibrosis, the airways fill with thick, sticky mucus, making it difficult to breathe. The thick mucus is also an ideal breeding ground for bacteria and fungi.
How many copies of a gene do you need to have cystic fibrosis?
The type of gene mutation is associated with the severity of the condition. Children need to inherit one copy of the gene from each parent in order to have the disease. If children inherit only one copy, they won't develop cystic fibrosis. However, they will be carriers and could pass the gene to their own children.
When can cystic fibrosis be diagnosed?
In the U.S., because of newborn screening, cystic fibrosis can be diagnosed within the first month of life, before symptoms develop. But people born before newborn screening became available may not be diagnosed until the signs and symptoms of CF show up.
How does exercise help cystic fibrosis?
How exercise benefits cystic fibrosis. Improves lung function by loosening mucus and causing coughing. Builds stamina. Improves mood. Strengthens muscles, especially the breathing muscles and heart. Improves the quality of sleep. Helps with weight management. Slows the rate of decline in FEV1 and may show small increases in FEV 1.
Can you lose salt in CF?
While losing too much salt is rarely a problem in people with CF, it does happen on occasion . Losing too much salt can lead to dehydration and heatstroke. Symptoms of too little salt include: 2
Is aerobic exercise good for CF?
Helps maintain healthy bones 4. Usually, aerobic exercise is considered a supplement to other airway clearance techniques; however, in a small proportion of adults with CF ages 20-40, exercise is their primary airway clearance method.
Can cystic fibrosis be replaced with exercise?
People with cystic fibrosis should never substitute exercise for airway clearance techniques without consulting their medical team. 5. “If exercise could be purchased in a pill, it would be the single most widely prescribed and beneficial medicine in the nation.”. – Robert H. Butler.
What is the function of CFTR protein?
The CFTR protein regulates the transport of salts into and out of cells. When mutated, the protein does not function normally, and the balance of fluids and salts is disrupted. As a result, cells produce a thick, sticky type of mucus that can obstruct airways and harbor the growth of infectious bacteria. Cystic fibrosis affects the lungs quite severely, but also affects many other organs of the body.
Where did cystic fibrosis originate?
Origins. The most common mutation leading to cystic fibrosis is f508del. Researchers have traced the origins of the mutation to two separate events. It was first introduced into European populations about 50,000 years ago, possibly through the Basques of Spain, who have a notably high rate of cystic fibrosis today.
Which bacteria binds to CFTR to gain entry into intestinal cells?
Another theory points to typhoid as the source of the advantage of the cystic fibrosis gene. Salmonella typhi, the bacteria that causes typhoid fever, binds to CFTR to gain entry into intestinal cells. In a study in mice with defective CFTR, S. typhi bacteria were prevented from entering the intestinal cells.
Does cystic fibrosis cause diarrhea?
One theory is that it may give resistance to cholera or other illnesses that cause diarrhea and dehydration. The logic of this theory is that the altered salt and water balance may protect against dehydration during bouts of severe diarrhea.
Can cystic fibrosis be passed on?
Until recently, children born with cystic fibrosis rarely survived past the age of five. However, 1 in 20 people of European ancestry are carriers. That suggests that the gene may confer a survival advantage, in addition to causing a deadly disease, since a gene leading to such a deadly disease would otherwise tend to dwindle in the population due to selective pressure against it.
Does cholera have a survival advantage?
However, scientists have subsequently calculated the effects of such a survival advantage against cholera and typhoid and determined that a gene offering protection against those illnesses would not confer enough of a selective advantage to drive the prevalence of the gene to its high levels among Europeans.
Is cystic fibrosis a mutation?
The evolution of cystic fibrosis as a mutation that confers an advantage in carriers and a deadly disease in those with two copies, is likely to be complex, and may involve protection against more than one type of illness. Scientists are still exploring the evolutionary role of the cystic fibrosis gene.
What Is Cystic Fibrosis?
At lunch, Lindsay often gets bored with having the same old conversation with her friends:
What do people with CF need to stay healthy?
In addition, people with CF have some specific nutritional needs to help them stay healthy. Here are some of the nutrients they need to get more of: Protein. About 15% to 20% of the calories a teen with CF eats should come from foods rich in protein, like meat, eggs, soy foods, fish, nuts, or beans. Iron.
How many calories should a teenager with CF eat?
In general, teens with CF may need more calories a day than others in their age group — that's about 2,900 to 4,500 calories daily, depending on the individual. What are all those calories for? Like every other teenager, girls and guys with CF need calories to fuel their growth during puberty. They just need more of them.
Why do teens get sick from CF?
This mucus can also keep the intestines from absorbing important nutrients like fat and vitamins from food, which means that teens with CF may be short and underweight for their age, and they may get sick a lot because their bodies can't fight infections well.
Why do people with CF need extra calories?
People with CF need extra calories and nutrients to help them fight infection and keep their lungs strong, particularly if they get sick with colds or the flu. Charly Tells Her Teacher She Has Cystic Fibrosis from KidsHealth Videos on Vimeo. Charly Tells Her Teacher She Has Cystic Fibrosis. Play.
How many calories are in a CF meal plan?
Check out this sample meal plan that provides approximately 3,750 calories. The links to some of these foods will give you recipes for high-calorie foods that teens with CF can make: Breakfast — 3 frozen pancakes with 1 tablespoon butter and 3 tablespoons syrup; ½ cup of strawberries; Mighty Milk.
How to replace salt in CF?
A good way to replace this salt is by adding salt to food and eating salty snacks. A CF dietitian (a specially trained food and nutrition expert) may recommend sports drinks for after sports practice or gym class, especially during hot weather.
What happens if CFTR is not working?
If the CFTR protein is not working normally, clearance of bacteria and particles from the lungs is impaired. Either correcting the dysfunction of this protein or dealing with the downstream consequences is key to developing therapies that will modify the natural history of CF. See the entire Cystic Fibrosis Chapter.
How does lung disease affect the cost of treatment?
The costs of treatment escalate as the patient becomes sicker. Treatment of lung disease is likely to involve repeated courses of expensive intravenous antibiotics. Patients being treated for atypical Mycobacteria are prescribed particularly expensive medications. As respiratory disease worsens, home oxygen and noninvasive ventilation may be required, and eventually very prolonged hospital stays are likely. Maintenance of good nutrition may require placement of a gastrostomy for supplemental enteral feeds. Treatment of CF-related diabetes, liver disease and bone disease adds to the rising costs, and these may culminate in the costs of lung transplantation.
What is CFTR gene?
CFTR is a widely expressed, multifunctional protein. Its best-known function, that of a chloride channel, is responsible for the abnormal sweat test and is also responsible for some disease manifestations such as electrolyte depletion and heat exhaustion. However, it is naïve to believe that the same functions are responsible for all disease manifestations, and there is increasing evidence that dysregulation of the epithelial sodium channel ENaC is more likely responsible for the pulmonary disease. Recently, the nomenclature of CFTR gene mutations has been revised ( www.cdc.gov/dls/ genetics/rmmaterials/pdf/HGVSNomenclature.pdf ); however, this chapter uses the old nomenclature because it is also used in the ECFS reports. CFTR mutations have been divided into six classes (table 2): classes I–III are severe, associated with pancreatic insufficiency; classes IV–VI are mild and pancreatic sufficient. A combination of a mild and severe mutation predicts a mild (pancreatic sufficient) phenotype. However, there is considerable individual variation within genotypes, which has been related to modifications within the CFTR genetic locus itself, modifier genes elsewhere in the karyotype, and environmental factors; these are the subject of active research. Predicting prognosis in an individual from his or her genotype is not possible.
What is the most comprehensive and up-to-date collection of epidemiological data for CF across Europe?
The most comprehensive and up-to-date collection of epidemiological data for CF across Europe is the registry maintained by the European Cystic Fibrosis Society (ECFS) (www.ecfs.eu). Data are submitted to the registry by both national CF registries and individual CF centres throughout Europe. The registry collects data from 25 000 CF patients in 21 countries and produces annual summary reports.
What is CFTR produced after?
Mature CFTR is produced after complex post-transcriptional and post-translational processing, which has implications both for prognosis and modern, genotype-specific, therapy. The protein has a key function in regulating the amount of water in the airway surface liquid.
Is CF a white disease?
Cystic fibrosis (CF) is the commonest lethal inherited disease of white races, but it should be noted that in multi-racial Europe, no ethnic group is exempt from the disease, although prevalence varies across the continent.
Is there a decline in the prevalence of CF?
It is intriguing to note that in countries where newborn screening for CF has been introduced, there has been a decline in the prevalence of CF. This may at least in part be due to diagnosis of the first CF child in the family before a second one is conceived, thus giving couples reproductive choices after the birth of a first CF child.
Overview
Symptoms
Causes
Risk Factors
Complications
Prevention
- In the U.S., because of newborn screening, cystic fibrosis can be diagnosed within the first month of life, before symptoms develop. But people born before newborn screening became available may not be diagnosed until the signs and symptoms of CFshow up. Cystic fibrosis signs and symptoms vary, depending on the severity of the disease. Even in the same person, symptoms …