Female siblings with Pendred's syndrome were admitted to our clinic. T
he abnormality of the acoustic structure was examined by MRI. Bilatera
l enlargement of the vestibular aqueduct and a prominently marked endo
lymphatic sac were found on MRI. These findings seemed likely to repre
sent a Mondini deformity. Acoustic structure in Pendred's syndrome was
examined here by MRI for the first time. We examined their HLA-DR loc
us as a genetic marker using the affected sib-pair method preliminary.
HLA typing might be a diagnostic criteria of Pendred's syndrome, alth
ough the present siblings possessed 2 HLA genes in common.