Ovotesticular Disorder of Sexual Development (True Hermaphroditism)

Objectives: To determine the mechanism for the 46,XX/46,XY karyotype observed in a patient with an ovotesticular disorder of sexual development (ie, true hermaphroditism). Methods: Cytogenetic, molecular cytogenetic, and molecular DNA analyses were performed on the blood, skin, and left and right gonadal tissue from 2 surgical procedures. The results of these studies were used to determine whether the ovotesticular disorder of sexual development resulted from mosaicism or tetragametic chimerism. Results: Cytogenetic and molecular analyses revealed a mixture of 46,XX and 46,XY cells in most tissues. DNA analysis from the gonadal tissues from surgeries 1 and 2 was performed. Highly polymorphic loci from 12 different chromosomes were examined for the presence of ≥1 paternal or maternal alleles. Three loci were highly informative: D14S544 (14q32.2), DS14S583 (14q21.3), and SE33 (6q14). Each demonstrated the presence of 2 paternal and 2 maternal alleles, indicating that the ovotesticular disorder of sexual development resulted from tetragametic chimerism. Conclusions: Based on the findings of the cytogenetic, molecular cytogenetic, and DNA analyses of the polymorphic markers from several different loci, it was confirmed that the patient had tetragametic chimerism. This case has assisted in increasing our knowledge of the possible mechanisms causing this rare and complex disorder.