Differentiating Müllerian Agenesis from Androgen Insensitivity Syndrome

Clinical Presentation and Diagnostic Features

Primary amenorrhea in otherwise normally developed females with normal female external genitalia and normal breast development at puberty is a common presentation in both conditions, with normal female testosterone levels and 46,XX karyotype in Müllerian agenesis, and male-range testosterone levels and 46,XY karyotype in Complete Androgen Insensitivity Syndrome (CAIS) 1
The presence of testes, which may be intra-abdominal, inguinal, or labial, and sparse or absent pubic and axillary hair due to androgen receptor defects, are characteristic of CAIS 1

The American College of Obstetricians and Gynecologists and other medical societies recommend a diagnostic algorithm that includes initial hormonal assessment, karyotype analysis, and imaging evaluation to differentiate between Müllerian agenesis and CAIS, with karyotype analysis being the definitive test 1