A healthy 23-year-old woman with amenorrhea was examined at the Mendel Institute. She had been amenorrheic for 4 years, and had not responded to hormone treatment. We therefore decided to study her family tree and karyotype. We describe the results of our study here: the patient was found to have gonadal dysgenesis, caused by translocation of a fragment of the X to a 12 chromosome, resulting from a break at q21, at the end of the q-arm.