<prompt> A 16-year-old female presents with Primary Amenorrhea. Examination shows a Short Blind Vagina, with absent Uterus. The Next Investigation of choice is:KaryotypingIVPGonadotrophin levelsSerum prolactin  <response>: Ans. is a, i.e. KaryotypingRef: Jeffcoate 7thed, p198; CGDT 10thed, p931 Fig. 56-2A female presenting with absent uterus and short blind vagina:DDs that should come to your mind are:Mullerian dysgenesis and Testicular feminizing syndrome or male pseudohermaphroditismPresentationMullerian AgenesisAndrogen InsensitivityInheritance patternSporadicX-linked recessiveKaryotype46XX46XYBreast developmentYesYesAxillary and pubic hairYesNoUterusNoNoGonadOvaryTestisTestosteroneFemale levelsMale levelsAssociated anomaliesYesNoSo, the best way to differentiate between the two is to do karyotyping or chromatinbarr body test, which comes positive barr body present in 46XX and negative barr body absent in case of 46XY Genotype. 