WBR0479

Author	[[PageAuthor::Rim Halaby, M.D. [1]]]
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Immunology, MainCategory::Pathology
Sub Category	SubCategory::Head and Neck
Prompt	[[Prompt::A 6 month old boy is brought by his mother for recurrent infections. Following appropriate work-up, the patient's mother is told that her son is a candidate for bone marrow transplantation (BMT) to cure his condition. When asked, the physician informs that mother that her son has an inherited X-linked disease that causes a defective interleukin (IL)-2 receptor. Which of the following is the most likely finding during this patient's physical exam and work-up pre-op?]]
Answer A	AnswerA::Absent pus formation
Answer A Explanation	AnswerAExp::Absent pus formation is seen in patients with leukocyte adhesion deficiency (LAD).
Answer B	AnswerB::Partial albinism
Answer B Explanation	AnswerBExp::Partial albinism is seen in patients with Chediak-Higashi syndrome.
Answer C	AnswerC::Retained primary teeth
Answer C Explanation	AnswerCExp::Retained primary teeth is a common finding in patients with Job's syndrome (Hyper-IgE syndrome).
Answer D	AnswerD::Absent palatine tonsils
Answer D Explanation	AnswerDExp::Absent palatine tonsils is a finding in Bruton's agammaglobulinemia
Answer E	AnswerE::Absent thymic shadow on chest xray
Answer E Explanation	AnswerEExp::Absent thymic shadow, a finding due to thymic hypoplasia, is seen in patients with SCID.
Right Answer	RightAnswer::E
Explanation	[[Explanation::Severe combined immunodeficiency (SCID) is an immunological disease that is commonly inherited by an X-linked pattern. It is characterized by recurrent infections due to deficiency of both B-cells and T-cells. There are several causes of SCID; commonly IL-2 receptor defect and adenosine deaminase deficiency are the culprit. Because of T-cell deficiency in SCID, patients will have thymic hypoplasia that is manifested as an absent thymic shadow on chest xray. Educational Objective: SCID is characterized by T-cell and B-cell deficiencies. Thymic hypoplasia with absent thymic shadow on chest xray is characteristic of SCID. References: First Aid 2014 page 213]]
Approved	Approved::Yes
Keyword	WBRKeyword::thymic, WBRKeyword::hypoplasia, WBRKeyword::thymus, WBRKeyword::SCID, WBRKeyword::severe, WBRKeyword::combined, WBRKeyword::immunodeficiency, WBRKeyword::severe combined immunodeficiency, WBRKeyword::interleukin, WBRKeyword::receptor, WBRKeyword::2, WBRKeyword::adenosine, WBRKeyword::deaminase, WBRKeyword::deficiency, WBRKeyword::absent, WBRKeyword::thymic, WBRKeyword::shadow, WBRKeyword::xray
Linked Question	Linked::
Order in Linked Questions	LinkedOrder::