Molecular Analysis of Parthenogenetic Chimerism in a 46,XX/46,XY Patient with Idiopathic Oligoasthenoteratozoospermia.

Introduction: Parthenogenetic chimera is an extremely rare condition in human. Very few patients with parthenogenetic chimerism with XX/XY cells have been identified. Case Presentation: We report the clinical findings and molecular analysis of chimerism with a 46,XX/46,XY karyotype in a patient presenting idiopathic oligoasthenoteratozoospermia (OAT). To clarify the mechanism of chimera formation, short tandem repeat analysis using 21 loci was carried out. Quantitation of alleles in D6S1043, D12S391, fibrinogen alpha chain, and amelogenin revealed double paternal and one maternal genetic contribution to the patient, which is consistent with a parthenogenetic chimerism. The likely mechanism of chimerism formation was also discussed, followed by a literature review. Conclusion: This is the first documented case of parthenogenetic chimerism in an adult male with XX/XY cells presenting OAT. Improved cell sampling and more sensitive and specific detection methods are necessary to identify more patients with XX/XY chimerism for systematic studies on this condition in the future. Established Facts: Parthenogenetic chimera, resulting from endoreplication of the female pronucleus via mitotic divisions, is an extremely rare condition. Very few patients with parthenogenetic chimerism with XX/XY cells have been identified. The phenotypes of these patients vary from typical male genitalia to different degrees of ambiguous genitalia, and even to ovotesticular disorder of sex development. However, these patients' fertility ability in adulthood was not assessed since their conditions were usually discovered before childhood. [ABSTRACT FROM AUTHOR]