Pendred syndrome and non-syndromic recessive deafness associated with enlarged 
vestibular aqueduct (NSRD with EVA) are caused by mutations in the SLC26A4 (PDS) 
gene. Unlike NSRD with EVA, Pendred syndrome is characterized by goiter, which 
may be present after early adulthood. However, the clinical diagnosis of these 
two disorders is difficult in deaf children. Expression of the SLC26A4 gene may 
be responsible for iodide transport in the thyroid as well as for formation and 
function of the inner ear. Here, we analyzed the SLC26A4 gene and performed 
thyroid function tests (FT3, FT4, TSH, and Thyroglobulin) on six congenitally 
deaf infants (mean age 2.7 years) with EVA. Mutation of the SLC26A4 gene was 
identified in five patients: four were compound heterozygous (H723R/919-2A>G, 
H723R/IVS15+5G>A, H723R/R581S, IVS7-2A>G/IVS8+1G>A), the fifth had a frameshift 
mutation (322delC). All the patients demonstrated an elevation of serum 
thyroglobulin level. FT3 level was elevated in four of the five patients. The 
patient who did not have a detectable gene mutation showed normal thyroid 
function. We conclude that the mutations in the SLC26A4 gene identified here are 
highly associated with high serum thyroglobulin levels in congenital and 
deafness infants. These mutations may be of value for the diagnosis of Pendred 
syndrome and NSRD with EVA.