Kartagener Syndrome Mnemonic for Effective Learning

Kartagener Syndrome is a disease that is inherited in an autosomal recessive pattern. In an autosomal recessive disorder, two mutated genes are inherited from each parent. These disorders are usually passed on by two carriers. With each pregnancy, two carriers have a 25 percent chance of having an unaffected child with two normal genes, a 50 percent chance of having an unaffected child who is also a carrier, and a 25 percent chance of having an affected child with two recessive genes.

Dynein is a family of cytoskeletal motor proteins that move along microtubules in cells. They convert the chemical energy stored in ATP to mechanical work. Dynein transports various cellular cargos, provides forces and displacements important in mitosis, and drives the beat of eukaryotic cilia and flagella. All of these functions rely on dynein's ability to move towards the minus-end of the microtubules, known as retrograde transport. In Kartagener Syndrome, the cilia on the patient's cells are not motile due to the defective dynein arm.

Due to the dynein arm defect, males with Kartagener Syndrome lose motility of the sperm's cilia, leading to near 100% infertility. In females there is reduced fertility or complications if fertilization occurs (e.g. ectopic pregnancy) due to defective ovum transport secondary to the dyskinetic motion of oviductal cilia.

In Kartagener Syndrome, the cilia that lines the flagellum of sperm cells is defective due to the dynein arm defect leading to sperm immotility.

Females with Kartagener Syndrome have a defective ovum transport because of dyskinetic motion of oviductal cilia caused by the dynein arm defect.

Ciliary motility plays a part in the transport of the ovum through the fallopian tube. The fertilized egg is expected to travel to the uterus in 3 to 4 days after fertilization. Due to the ciliary defect in the fallopian tube in Kartagener Syndrome patients, the fertilized egg may stay in the fallopian tube, leading to an ectopic pregnancy.

Cilia in airways help to clear mucus, dust and microbes out of the airways. In Kartagener Syndrome, the defective cilia can lead to infections that can damage the walls of the airways which leads to bronchiectasis.

In Kartagener Syndrome, the defective cilia can lead to opportunistic infections due to inability clearing out microbes leading to recurrent sinusitis.

Chronic ear infections can be seen in patients with Kartagener Syndrome due to the defective cilia in the ear. This prevents the effective clearance of the mucus and microbes from the ears leading to risk of chronic ear infections. Paranasal sinuses and the middle ear are connected via the Eustachian tubes in the posterior pharynx, resulting in opportunity for viruses and bacteria to transport and infect seemingly different areas of the upper airway.

Conductive hearing loss occurs when there is a problem transferring sound waves anywhere along the pathway through the outer ear, tympanic membrane (eardrum), or middle ear (ossicles). Patients with Kartagener Syndrome can present with chronic middle ear infections interrupting audiological function.

Patients with Kartagener Syndrome have Dextrocardia with situs inversus. Situs inversus refers to the mirror-image reversal of the organs in the chest and abdominal cavity. In people affected by dextrocardia, the tip of the heart points towards the right side of the chest instead of the left side. Most patients with this display no sign or symptom and it is not discovered until they have a chest x-ray done.

Nitric oxide is continually synthesised in the respiratory epithelium and is upregulated in response to infection or inflammation. Although Kartagener Syndrome patients have chronic infections, nasal nitric oxide in such patients is markedly reduced and is used as a screening test for this condition.