Student guide for the preparation of USMLE Step 1
Facts that might help you with your performance
Autosomical Recesive disease
Prevalence: 1: 40,000 – 60,000
Considered to be part of Primary Ciliary Diskinesia, when situs inversus is present
Also called Immotile Cilia Syndrome
Caused by multiple mutations that encodes for the DYNEIN gen
Motor Protein that forms the arms in the microtubule doublets, wich provides
motility of cilia
Any defect in this protein will cause:
1.- Impaired movement of cilia:
Specifically, in the Respiratory epithelium wich confers
protection by the clearance of any foreing particles that
enters from mouth-nose through the bronchioles
Genes mutated related with the presentation of this disease are:
DYNEIN AXONEMAL INTERMEDIATE CHAIN 1 (DNAI1)
Mutations in the coding region of this one account for Situs Inversus
DYNEIN AXONEMAL HEAVY CHAIN 5 (DNAH5)
Patients may have some or all features :
Rhinosinusitis and otitis media are cardinal features
Nasal discharge clear or purulent
Nasal polypoid hyperplasia
Middle ear effusion
Theory: Random distribution of internal organ during embriogenesis probably due to the
absense of the ciliary activity wich is responsible for the normal distribution of the organs
( Afzelius, 1995)
•Physical examination: auscultation of cardiac sounds on the right of the chest
•Thoracic roentogram (X ray): right sided heart, aorta and gastric bubble placed on the
righ also, thoracic scholiosis,
“Three in bud” sign indicative of obstructive bronchiolitis, due to a mucus plug
•EKG: Negative P wave
• QRS complex and T wave in lead I
• right lower quadrant QRS axis
•regression of QRS amplitude from V1 to V6 (as the heart is on the opposite side).
Def: common complication due to recurrent pulmonary infections wich
destroy pulmonary parenchima and dilate bronchial walls permanently .
Chronic productive cough (compensatory mechanism for the lack of
effective mucociliary clearance.
Recurrent episodes of Pneumonia or Bronchitis
Coarse Rales and wheezing
Low SO2 in acute episodes
Bacterial cultures of lower respiratory secretions most commonly yield
nontypeable H. Influenzae, S. Aureus, S. Pneumoniae and P. Aeruginosa in
some older patients ( but not common as Cystic Fibrosis!!!)
Mainly preserve pulmonary function ( preventive and profilactic
Nebulizations if needed
Annual Influenza vaccine
Antibiotics, intravenous or oral and continuous or intermittent, are used to
treat upper and lower airway infections.
The choice of using antibiotics Depends on the results of cultures!
This Disease also presents with Bronchiectasis because of abnormally visced
mucus and Infertility is because of absence of vasa deferens, wich results in
Azospermia, not hipomotility! Eyes wide open with this facts!...
Allergic bronchopulmonary aspergillosisIdiopathic nasal polyposis
Inhalation of toxic substances
Samter triad (asthma, aspirin sensitivity and nasal/ethmoidal polyposis)…
Author Drew Miller and cols.
Primary Ciliary Dyskinesia/ Kartagener Syndrome-Clinical and Genetic Aspects
Author: Masumi Akita and cols.
Síndrome de Kartagener: Diagnóstico tardío,
Author: A. Sánchez Muñoz and cols.
Diagnóstico Prenatal de Situs Inversus
Author:Mario Paublo and cols.
Raiographic features of Kartagener Syndrome
More images and signs:
First Aid for the Basic Sciences : Organ Systems , Tao Le and Kendall Krause