A 21-year-old woman presents with complaints of primary amenorrhoea. Her height is 153 cms, weight is 51 kg. She has well-developed breasts. She has no public or axillary hair and no hirsutism. Which of the following is the most probable diagnosis-
**Core Concept**
Primary amenorrhoea is a condition where a woman has not experienced her first menstrual period by the age of 16 years. This condition can be caused by a variety of factors, including genetic, anatomical, and hormonal abnormalities.
**Why the Correct Answer is Right**
The patient's presentation of primary amenorrhoea, well-developed breasts, and absence of pubic or axillary hair suggests an androgen deficiency. In this case, the most probable diagnosis is Turner syndrome, a genetic disorder characterized by the absence of one X chromosome (45,X). Individuals with Turner syndrome often have ovarian dysgenesis, leading to estrogen production but a deficiency of androgens. This results in normal breast development but a lack of pubic and axillary hair.
**Why Each Wrong Option is Incorrect**
**Option A:** This option would be incorrect because it suggests a diagnosis of androgen insensitivity syndrome (AIS), which typically presents with well-developed breasts and pubic and axillary hair due to the presence of androgen receptors, but the individual is resistant to the effects of androgens.
**Option B:** This option would be incorrect because it suggests a diagnosis of hypothalamic amenorrhoea, which is typically seen in thin or athletic women with a high body mass index (BMI) or those with a history of eating disorders. This patient's BMI is low, but her presentation is more suggestive of a genetic or anatomical abnormality.
**Option C:** This option would be incorrect because it suggests a diagnosis of congenital adrenal hyperplasia (CAH), which typically presents with virilization (excessive hair growth, deep voice, etc.) due to an excess of androgens.
**Option D:** This option would be incorrect because it suggests a diagnosis of polycystic ovary syndrome (PCOS), which typically presents with oligomenorrhea or amenorrhea, hirsutism, and obesity.
**Clinical Pearl / High-Yield Fact**
Turner syndrome is often associated with short stature, and individuals with this condition should be evaluated for growth hormone deficiency.
**Correct Answer:** C.