Besides clinical and radiological assessments, molecular and functional studies are essential for the correct diagnosis of Pendred syndrome and non-syndromic EVA.
Loss or reduction in the function of pendrin results in both syndromic (Pendred syndrome) and non-syndromic (non-syndromic enlarged vestibular aqueduct (ns-EVA)) hearing loss.
The shape and function of thyroid were confirmed to be normal by thyroid ultrasound scan and thyroid hormone assays in 19 of the 20 patients with EVA or other inner ear malformation except one who had cystoid change in the right side of thyroid.No Pendred syndrome was diagnosed.