**Question:** A 19-year-old patient complains of primary amenorrhea. She had well-developed breast and public hair but on examination there was absence of uterus and vagina. Likely diagnosis is:

A. Turner syndrome
B. Klinefelter syndrome
C. CAH (Cortisol deficiency)
D. 46, XX karyotype

**Correct Answer:** A. Turner syndrome

**Core Concept:**
Primary amenorrhea refers to the absence of menstruation by the expected menarche age (14-16 years). In this case, the patient presents with well-developed breasts and pubic hair, which is consistent with a female patient. However, the absence of a uterus and vagina on examination suggests a developmental disorder.

**Why the Correct Answer is Right:** Turner syndrome is a genetic disorder caused by the complete or partial absence of one X chromosome (45, X or 45, XO). In these cases, the development of the female reproductive system is impaired, leading to primary amenorrhea. The patient may have ambiguous genitalia, short stature, and other characteristics, which are present in this case.

**Why Each Wrong Option is Incorrect:**

A. Klinefelter syndrome (47, XXY) is a male karyotype disorder characterized by enlarged testes, gynecomastia, and infertility, which are not present in this case.
B. CAH (Cortisol deficiency) is a disorder affecting adrenal function, leading to adrenal insufficiency, salt-wasting crisis, and hyperkalemia. These symptoms are not mentioned in the patient's case.
C. CAH (Cortisol deficiency) is a disorder affecting adrenal function, leading to adrenal insufficiency, salt-wasting crisis, and hyperkalemia. These symptoms are not mentioned in the patient's case.
D. A 46, XX karyotype patient would have a normal female reproductive system. This option is incorrect based on the patient's condition.

**Clinical Pearl:**
Turner syndrome is a common cause of primary amenorrhea, especially in females with ambiguous genitalia. Early diagnosis and management can prevent complications such as osteoporosis, cardiac issues, and reduced fertility.

**Why Each Wrong Option is Incorrect:**

A. Klinefelter syndrome is a male karyotype disorder, which does not explain the absence of a uterus and vagina in this female patient.
B. CAH (Cortisol deficiency) is a disorder affecting adrenal function, leading to adrenal insufficiency, salt-wasting crisis, and hyperkalemia. These symptoms are not mentioned in the patient's case.
C. CAH (Cortisol deficiency) is a disorder affecting adrenal function, leading to adrenal insufficiency, salt-wasting crisis, and hyperkalemia. These symptoms are not mentioned in the patient's case.
D. A 46, XX karyotype patient would have a normal female reproductive system. This option is incorrect based on the