Cystic fibrosis

Health problems associated with cystic fibrosis
Cystic fibrosis has an autosomal recessive pattern of inheritance
The CFTR protein is a channel protein that controls the flow of H2O and Cl− ions in and out of cells inside the lungs. When the CFTR protein is working correctly, ions freely flow in and out of the cells. However, when the CFTR protein is malfunctioning, these ions cannot flow out of the cell due to a blocked channel. This causes cystic fibrosis, characterized by the buildup of thick mucus in the lungs.
The location of the CFTR gene on chromosome 7
Intracytoplasmic sperm injection can be used to provide fertility for men with cystic fibrosis
Dorothy Hansine Andersen first described cystic fibrosis in 1938.

Genetic disorder that affects mostly the lungs, but also the pancreas, liver, kidneys, and intestine.

- Cystic fibrosis

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Inflammatory condition of the lung primarily affecting the small air sacs known as alveoli.

Chest X-ray of a pneumonia caused by influenza and Haemophilus influenzae, with patchy consolidations, mainly in the right upper lobe (arrow)
Main symptoms of infectious pneumonia
The bacterium Streptococcus pneumoniae, a common cause of pneumonia, imaged by an electron microscope
Cavitating pneumonia due to MRSA as seen on a CT scan
A chest x-ray of a patient with severe viral pneumonia due to SARS
Pneumonia fills the lung's alveoli with fluid, hindering oxygenation. The alveolus on the left is normal, whereas the one on the right is full of fluid from pneumonia.
A chest X-ray showing a very prominent wedge-shaped area of airspace consolidation in the right lung characteristic of acute bacterial lobar pneumonia
CT of the chest demonstrating right-sided pneumonia (left side of the image)
A pleural effusion: as seen on chest X-ray. The A arrow indicates fluid layering in the right chest. The B arrow indicates the width of the right lung. The volume of the lung is reduced because of the collection of fluid around the lung.
Deaths from lower respiratory infections per million persons in 2012
WPA poster, 1936/1937
Pneumonia seen by ultrasound
Right middle lobe pneumonia in a child as seen on plain X-ray

Risk factors for pneumonia include cystic fibrosis, chronic obstructive pulmonary disease (COPD), sickle cell disease, asthma, diabetes, heart failure, a history of smoking, a poor ability to cough (such as following a stroke), and a weak immune system.


Inflammation of the mucous membranes that line the sinuses resulting in symptoms that may include thick nasal mucus, a plugged nose, and facial pain.

A CT scan showing sinusitis of the ethmoid sinus
Illustration depicting sinusitis
CT of chronic sinusitis
CT scan of chronic sinusitis, showing a filled right maxillary sinus with sclerotic thickened bone.
MRI image showing sinusitis. Edema and mucosal thickening appears in both maxillary sinuses.
Maxillary sinusitis caused by a dental infection associated with periorbital cellulitis
Frontal sinusitis
X-ray of left-sided maxillary sinusitis marked by an arrow. There is lack of the air transparency indicating fluid in contrast to the other side.

Recurrent episodes are more likely in persons with asthma, cystic fibrosis, and poor immune function.

Failure to thrive

Failure to thrive (FTT), also known as weight faltering or faltering growth, indicates insufficient weight gain or absence of appropriate physical growth in children.

Disorders that cause difficulties absorbing or digesting nutrients, such as Crohn's disease, cystic fibrosis, or celiac disease, can present with abdominal symptoms.

Lung transplantation

Surgical procedure in which one or both lungs are replaced by lungs from a donor.

Illustration showing the process of a lung transplant. In figure A, the airway and blood vessels between a recipient’s diseased right lung and heart are cut. The inset image shows the location of the lungs and heart in the body. In figure B, a healthy donor lung is stitched to the recipient’s blood vessels and airway.
Incision scarring from a double lung transplant
Micrograph showing lung transplant rejection. Lung biopsy. H&E stain.

With other lung diseases such as cystic fibrosis, it is imperative that a recipient receive two lungs.

Cystic fibrosis transmembrane conductance regulator

Membrane protein and chloride channel in vertebrates that is encoded by the CFTR gene.

The location of the CFTR gene on chromosome 7
The Overall Structure of Human CFTR in the Dephosphorylated, ATP-Free Conformation. Domains are labeled. Made from PDB 5UAK
The CFTR protein is a channel protein that controls the flow of H2O and Cl− ions in and out of cells inside the lungs. When the CFTR protein is working correctly, as shown in Panel 1, ions freely flow in and out of the cells. However, when the CFTR protein is malfunctioning as in Panel 2, these ions cannot flow out of the cell due to blocked CFTR channels. This occurs in cystic fibrosis, characterized by the buildup of thick mucus in the lungs.

Mutations of the CFTR gene affecting chloride ion channel function lead to dysregulation of epithelial lining fluid (mucus) transport in the lung, pancreas and other organs, resulting in cystic fibrosis.

Genetic disorder

Health problem caused by one or more abnormalities in the genome.

A boy with Down syndrome, one of the most common genetic disorders
Diagram featuring examples of a disease located on each chromosome
Chromosomes in Down syndrome, the most common human condition due to aneuploidy. There are three chromosomes 21 (in the last row).
From personal genomics to gene therapy
Hereditary defects in enzymes are generally inherited in an autosomal fashion because there are more non-X chromosomes than X-chromosomes, and a recessive fashion because the enzymes from the unaffected genes are generally sufficient to prevent symptoms in carriers.
On the other hand, hereditary defects in structural proteins (such as osteogenesis imperfecta, Marfan's syndrome and many Ehlers–Danlos syndromes) are generally autosomal dominant, because it is enough that some components are defective to make the whole structure dysfunctional. This is a dominant-negative process, wherein a mutated gene product adversely affects the non-mutated gene product within the same cell.

Examples of this type of disorder are albinism, medium-chain acyl-CoA dehydrogenase deficiency, cystic fibrosis, sickle cell disease, Tay–Sachs disease, Niemann–Pick disease, spinal muscular atrophy, and Roberts syndrome.


Pathological wound healing in which connective tissue replaces normal parenchymal tissue to the extent that it goes unchecked, leading to considerable tissue remodelling and the formation of permanent scar tissue.

Micrograph of a heart showing fibrosis (yellow – left of image) and amyloid deposition (brown – right of image). Movat's stain.
Micrograph showing cirrhosis of the liver. The tissue in this example is stained with a trichrome stain, in which fibrosis is colored blue. The red areas are the nodular liver tissue
Bridging fibrosis in a Wistar rat following a six-week course of thioacetamide. Sirius Red stain
Healthy myocardium versus interstitial fibrosis in dilated cardiomyopathy. Alcian blue stain.
Replacement fibrosis in myocardial infarction, being boundless and dense.

Cystic fibrosis

Genetic testing

Used to identify changes in DNA sequence or chromosome structure.

The structure of the DNA double helix. The atoms in the structure are colour-coded by element and the detailed structures of two base pairs are shown in the bottom right.

Carrier testing - used to identify people who carry one copy of a gene mutation that, when present in two copies, causes a genetic disorder. This type of testing is offered to individuals who have a family history of a genetic disorder and to people in ethnic groups with an increased risk of specific genetic conditions. If both parents are tested, the test can provide information about a couple's risk of having a child with a genetic condition like cystic fibrosis.

Pseudomonas aeruginosa

Common encapsulated, Gram-negative, strict aerobic , Rod-shaped bacterium that can cause disease in plants and animals, including humans.

Pseudomonas aeruginosa in Petri dish.
Pigment production, growth on cetrimide agar, the oxidase test, plaque formation and Gram stain.
A culture dish with Pseudomonas
Gram-stained P. aeruginosa bacteria (pink-red rods)
Phagocytosis of P. aeruginosa by neutrophil in patient with bloodstream infection (Gram stain)
Production of pyocyanin, water-soluble green pigment of P. aeruginosa (left tube)
Pseudomonas aeruginosa fluorescence under UV illumination
The antibiogram of P. aeruginosa on Mueller–Hinton agar

The organism is considered opportunistic insofar as serious infection often occurs during existing diseases or conditions – most notably cystic fibrosis and traumatic burns.

Nail clubbing

Deformity of the finger or toe nails associated with a number of diseases, mostly of the heart and lungs.

Bone scan of a patient with HPOA
Clubbing of the fingernail: The red line shows the outline of a clubbed nail.
Schamroths window test, done to identify nail clubbing
Severe clubbing
Front view
Side views
Cyanotic nail beds

Clubbing is associated with lung cancer, lung infections, interstitial lung disease, cystic fibrosis, or cardiovascular disease.