## **Core Concept**
Primary amenorrhea refers to the absence of menstruation in a woman by the age of 16 years. It can result from various causes, including genetic, anatomical, and hormonal disorders. The conditions listed in the options are evaluated based on their association with primary amenorrhea.

## **Why the Correct Answer is Right**
Turner syndrome (Option ) is indeed associated with primary amenorrhea due to ovarian dysgenesis leading to gonadal dysfunction. Swyer syndrome (Option ) is also linked to primary amenorrhea because individuals have a 46,XY karyotype but develop as phenotypically female with gonadal dysgenesis. Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome (Option ) causes primary amenorrhea due to the congenital absence or underdevelopment of the vagina and uterus. However, testicular feminization, also known as complete androgen insensitivity syndrome (CAIS) (Option ), presents with primary amenorrhea as well, due to the inability of the body to respond to androgens, leading to a female phenotype despite having testes.

## **Why Each Wrong Option is Incorrect**
- **Option A:** Turner syndrome is associated with primary amenorrhea.
- **Option B:** Swyer syndrome is associated with primary amenorrhea.
- **Option C:** MRKH syndrome is associated with primary amenorrhea.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that in cases of primary amenorrhea, a thorough evaluation including genetic testing (karyotyping), pelvic ultrasound, and hormonal assays is crucial to identify the underlying cause.

## **Correct Answer:** .