16-year-old female presents with primary amenorrhoea with B/L inguinal hernia. She has normal sexual development with no pubic hair. USG shows no uterus and overies and a blind vagina. Diagonosis is
**Core Concept**
The patient's presentation of primary amenorrhea, bilateral inguinal hernias, and absence of sexual development with normal secondary sexual characteristics, along with the ultrasound findings of no uterus, ovaries, and a blind vagina, suggests a condition characterized by the presence of male internal genitalia in a phenotypically female individual.
**Why the Correct Answer is Right**
The correct diagnosis is androgen insensitivity syndrome (AIS), a condition where individuals with 46,XY karyotype and normal androgen production have a mutation in the androgen receptor gene, leading to resistance to androgens. This results in the development of male internal genitalia, including testes, but the external genitalia and secondary sexual characteristics remain female due to the insensitivity to androgens. The presence of bilateral inguinal hernias is a common finding in AIS due to the presence of undescended testes.
**Why Each Wrong Option is Incorrect**
* **Option A:** Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome is characterized by the absence of the upper part of the vagina and uterus, but it does not typically present with bilateral inguinal hernias or male internal genitalia.
* **Option B:** Congenital adrenal hyperplasia (CAH) can present with primary amenorrhea and virilization, but the ultrasound findings would typically show the presence of ovaries and a normal uterus.
* **Option C:** Swyer syndrome is characterized by a 46,XY karyotype and the presence of a normal uterus, but the external genitalia and secondary sexual characteristics are underdeveloped.
**Clinical Pearl / High-Yield Fact**
AIS is a condition where the presence of testes is not always detectable on physical examination, and the diagnosis is often made after the presence of undescended testes is confirmed on imaging studies.
**Correct Answer: D. Androgen insensitivity syndrome (AIS)**