[Diagnostic interest of Barr chromatin test in sex determination: about one case of male pseudohermaphrodism].

Abstract

Introduction: The Barr chromatin test is a medical cytogenetic test, very quick to make, consisting in determination of the percentage of Barr corpuscles that correspond to the condensation of the second X chromosome in female epithelial cells of mammal, which range between 20 and 50% the percentage of Barr corpuscles in male epithelial cells range between 2 and less than 5%). In the less developed countries where caryotype isn't realized, this test can give invaluable informations about individual sex. The aim of this study was to show the Barr chromatin test interest in the sexual ambiguity diagnosis orientation in some cases of these sexual ambiguities.

Patient and methods: To carry this study, we have done a Guard coloration on nude nucleus of epithelial cells taken on the cheeck internal side of our patient, a 19 years old woman that a gynaecologist had sent to us for sexual ambiguity. We have examinated the nude nucleus.

Results: None of the nude nucleus had showed a Barr corpuscle (0% of Barr corpuscles, corresponding to male chromatin sex).

Conclusion: This rate has gived us a Morris syndrome diagnosis orientation; the diagnosis was confirmed later by the surgery and by the removal histological study. When caryotype or molecular biology are not available, the Barr chromatin test can represent a substitute biological test that can contribute to some sexual ambiguity diagnosis.