Kartagener syndrome, a very rare yet life-threatening autosomal recessive disorder. It is a unique syndrome which was initially charactered by a classical triad of situs inversus, chronic sinusitis, and bronchiectasis. Later, male infertility was added to it. It is a classic example of how mutations at the genetic level can alter the orientation of major internal organs within the body.
Kartagener Syndrome is an autosomal recessive disorder where genetic mutations can cause anatomical disposition of thoracoabdominal viscera leading to the formation of mirror image of normal. In 1933 Kartagener described the condition as a triad of situs inversus, chronic sinusitis, and bronchiectasis. There is no cure for kartagener syndrome, however, the pathological condition is managed by strict medical treatment and therapy.
EPIDEMIOLOGY OF KARTAGENER’S SYNDROME:
According to the Research in Indian Journal Of Human Genetics, an estimation of 1 in every 30,000 live births, babies are born with Kartagener’s syndrome.
PATHOPHYSIOLOGY OF KARTAGENER’S SYNDROME:
Kartagener Syndrome is a subclass of primary ciliary dyskinesia in which there is a mutation in DNAI1 and DNAH5 genes both encoding dynein protein responsible for motility of cilia hence leading to ciliary dysfunction.
During the 3rd week of embryonal development, the endoderm of the trilaminar disc expresses cilia in its ventral aspect. The movement of cilia controls the concentration of certain molecules such as Nodal, LEFTY1, and LEFTY2 on the left side of the coelomic cavity which is responsible for the development of abdominal and thoracic viscera on the left side.
In embryo with primary ciliary dyskinesia, those molecules are not swept efficiently on the left side so, the left-sided organs will be developed on the right side resulting in the formation of mirror image of normal. This transposition of thoracoabdominal viscera is known as situs inversus.
20% of individuals with situs inversus may suffer from some additional problems such as chronic sinusitis, bronchiectasis, and infertility in the male.
In case of chronic sinusitis, dysfunction of cilia leads to impairment of mucociliary clearance of paranasal air sinuses predisposing the patient to certain bacterial infections such as Staphylococcus aureus, Pseudomonas aeroginosa etc.
As cilia of the upper respiratory tract are dysfunctional, there is pooling of secretion which predisposes to certain microbial infections ultimately ended up to necrosis, fibrosis and permanent dilation of bronchi and bronchiole and is referred to as bronchiectasis.
Kartagener’s syndrome hampers the motility of sperm leading to male infertility. According to some trials, it is also known to cause infertility in female due to ciliary dysfunction which affects cilia in the fallopian tube.
SYMPTOMS OF KARTAGENER’S SYNDROME
Since Kartagener’s syndrome is a genetic disorder, it is diagnosed early in life. A patient usually comes with the complaints of recurrent upper respiratory tract infections such as a chronic cough with purulent foul smelling sputum production, repeated nasal blockage, recurrent episodes of sinusitis. The patient may suffer from infertility especially in the case of a male which is diagnosed later in life.
Patient with Kartagener syndrome has primary ciliary dyskinesia and situs inversus totalis. In situs inversus totalis the position of the thoracoabdominal organ such as the heart, liver, spleen, the intestine is reversed. Hence, the diagnosis of left-sided appendicitis is misinterpreted.
Furthermore, a patient may present to a doctor with a nasal polyp, anosmia, hearing loss and occasionally clubbing of finger and toes.
DIAGNOSIS OF KARTAGENER’S SYNDROME:
Kartagener syndrome is suspected based on clinical signs and symptoms. On general examination, the apex beat would be felt on the right side and liver would be palpable on the left side. Chest X-ray would show dextrocardia, upon ultrasonography of abdomen shows liver on left side and spleen on the right side. HRCT chest shows dextrocardia with the right-sided aortic arch. Complete blood count would show neutrophil leucocytosis and C-reactive protein.
The diagnosis is confirmed by histopathology and biopsy examination of cilia present in the respiratory tract taken by brush sample or scrapping of nasal cavity or trachea, abnormalities in cilia is seen in the case of Kartagener Syndrome. However, genetic testing can also be used to confirm the diagnosis.
TREATMENT OF KARTEGENER’S SYNDROME:
Till date, there is no specific treatment for Kartagener syndrome, hence the cure of the cilia dysfunction is still a myth. However, the associated problems with Kartagener syndrome such as sinusitis, bronchiectasis is treated with medications.
Pulmonary diseases-Managing patient with pulmonary diseases is associated with enhanced mucus clearance, preventing repeated respiratory tract infections and preventing bacterial infections.
For mucus clearance, the cough should be promoted, postural drainage is enhanced.
Use of antibiotic is promoted for the bacterial infection usually after sputum culture.
For people with nasal congestion and sinusitis, nasal surgery is recommended.
Situs inversus– For situs inversus, there is no surgical intervention needed unless any pathological condition is present.
Male infertility– Male infertility is usually avoided by in vitro fertilization. Another option is artificial insemination from a sperm donor.
Being a genetic disorder, there is no absolute cure for Kartagener syndrome and failure to diagnose this condition may cause the patient to unnecessary and recurrent hospital admissions. However, the pathological conditions associated with it such as chronic sinusitis, bronchiectasis, hearing loss, anosmia etc. can be minimized by circumspective lifestyle and proper medications.