WBR0101

Author	[[PageAuthor::William J Gibson (Reviewed by Yazan Daaboul, M.D. and Rim Halaby, M.D. [1])]]
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Genetics
Sub Category	SubCategory::Pulmonology
Prompt	[[Prompt::A 25-year-old man, with a long history of pulmonary infections, presents to his primary care physician’s office complaining of a persistent cough and expectoration of foul-smelling greenish sputum for the past tw months. He explains that he has suffered from recurrent respiratory tract infections since birth. A few months ago, he was prescribed an antibiotic that helped him recover from a similar episode. The patient now seeks a more thorough investigation of his symptoms. On physical examination, pulmonary auscultation reveals diffuse crackles and rhonchi accompanied by a high pitched wheezing during expiration. A recent ECG and abdomninal CT scan of the patient are retrieved from the patient's medical chart and are shown below. Which of the following conditions is this patient most likely to also suffer from? ]]
Answer A	AnswerA::Milk allergies and diarrhea
Answer A Explanation	[[AnswerAExp::This finding is nonspecific but can be a feature of IgA deficiency, also an immunodeficiency syndrome but not associated with situs inversus.]]
Answer B	AnswerB::Ataxia
Answer B Explanation	[[AnswerBExp::Ataxia is a feature of ataxia telangiectasia, also an immunodeficiency syndrome but not associated with situs inversus.]]
Answer C	AnswerC::Spider angiomas
Answer C Explanation	[[AnswerCExp::Spider angiomas are a feature of ataxia telangiectasia, also an immunodeficiency syndrome but not associated with situs inversus.]]
Answer D	AnswerD::Eczema
Answer D Explanation	[[AnswerDExp::Eczema is a feature of Wischott-Aldrich syndrome and IgA deficieny both of which can cause recurrent pulmonary infections but would not cause situs inversus.]]
Answer E	AnswerE::Infertility
Answer E Explanation	[[AnswerEExp::Kartagener’s syndrome is caused by defects in ciliary proteins. Functional cilia are required for sperm motility, see explanation.]]
Right Answer	RightAnswer::E
Explanation	[[Explanation::The patient in this vignette is suffering from Kartagener’s syndrome: a rare, ciliopathic, autosomal recessive genetic disorder that causes a defect in the action of the cilia lining the respiratory tract (lower and upper, sinuses, eustachian tube, middle ear) and fallopian tube, and also of the flagella of sperm in males. The main consequence of impaired ciliary function is reduced or absent mucus clearance from the lungs, and susceptibility to chronic recurrent respiratory infections, including sinusitis, bronchitis, pneumonia, and otitis media. The distant heart sounds in the cardiac exam of this patient reveal the presence of situs inversus, where the heart actually lies in the right side of the chest. Educational Objective: Kartagener’s syndrome is associated with recurrent sinus and pulmonary infections, situs inversus, and infertility in males. References: First Aid 2014 page 78]]
Approved	Approved::Yes
Keyword	WBRKeyword::Genetics, WBRKeyword::Kartagener's, WBRKeyword::Cilia, WBRKeyword::Pulmonary, WBRKeyword::Infection, WBRKeyword::Pulmonary infection, WBRKeyword::Immunodeficiency
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