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 work-up?]] |
| 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. |
| Approved | Approved::No |
| 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:: |