BACKGROUND: Pendred-syndrome is an autosomal recessive disease that is 
classically characterised by sensorineural hearing loss and enlargement of the 
thyroid gland. The gene SLC26A4/PDS for the pendred-syndrome has been localised 
by linkage analysis on chromosome 7q31. This protein is expressed in the inner 
ear, thyroid gland, kidney and placenta. Functional analysis in Xenopus laevis 
oocytes revealed that it acts as an iodide/chloride and chloride/formate 
exchanger.
METHOD: Each of the exons and flanking splice regions of the SLC26A4/PDS gene 
was analysed by direct sequencing.
RESULTS: In the involved family two heterozygous mutations could be detected 
which results by combination in hearing loss and deafness.
CONCLUSION: By evidences of familial background in hearing loss and thyroid 
disorder it is reasonable to analyse the PDS gene for mutation to have early the 
possibility for medical care of linguistic development through hearing aid or 
CI-implantation.