MOLECULAR BIOLOGIC ANALYSES OF TETRAGAMETIC CHIMERISM IN A TRUE HERMAPHRODITE WITH 46,XX 46,XY/

Objective: To investigate the mechanism of the formation of a tetragam etic chimera with true hermaphroditism (46,XX/46,XY). Design: Molecula r biologic analyses. Setting: Outpatient clinic and laboratories of a university hospital. Subjects: A true hermaphrodite with 46,XX/46,XY a nd the parents. Main Outcome Analysis: Restriction fragment length pol ymorphism (RFLP) of the pseudoautosomal region on sex chromosomes. Res ults: Whereas a normal diploid individual showed two bands, the true h ermaphrodite showed four bands in the RFLP analyses. Evaluation of the molecular weights of the bands revealed two of them to be of maternal origin and the other two to be of paternal origin. Conclusion: The tw o cell lineages composing the true hermaphrodite are heterogeneous bec ause those originated from the fertilization of two genetically differ ent maternal haploid cells by two different spermatozoa.