A 9-year-old girl has a diffuse goitre and bilateral moderate sensorineural hearing loss detected on school screening. Thyroid function is euthyroid. The perchlorate discharge test is positive, indicating defective iodide organification. What is the diagnosis?
- A Hashimoto thyroiditis
- B Pendred syndrome ✓
- C Congenital dyshormonogenesis due to thyroperoxidase deficiency
- D Resistance to thyroid hormone
Correct answer: B. Pendred syndrome
Explanation
Pendred syndrome combines sensorineural deafness with partial iodide organification defect, caused by mutations in SLC26B4 encoding pendrin, an iodide-chloride transporter also expressed in the inner ear. The positive perchlorate discharge test confirms impaired organification. Isolated thyroperoxidase deficiency causes congenital hypothyroidism without deafness, Hashimoto thyroiditis is autoimmune with positive antibodies, and resistance to thyroid hormone presents with elevated thyroid hormones and nonsuppressible TSH.
Reference: Nelson Textbook of Pediatrics, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.