**Question:** All are features of Turner's syndrome except:

A. Short stature
B. Webbed neck
C. Gynecomastia
D. Broad chest

**Core Concept:** Turner's syndrome is a genetic disorder characterized by partial or complete absence of one of the two X chromosomes in females. It presents with a range of clinical features due to the underdeveloped ovaries and the absence of estrogen production.

**Why the Correct Answer is Right:** Gynecomastia is not a feature of Turner's syndrome. In contrast to Turner's, gynecomastia is a condition characterized by the enlargement of male breast tissue due to excess estrogen production. In Turner's syndrome, the ovaries are underdeveloped and produce insufficient estrogen, resulting in characteristic features like short stature, webbed neck, and arched palate.

**Why Each Wrong Option is Incorrect:**

A. Short stature: Turner's syndrome presents with short stature due to impaired growth hormone secretion and underdeveloped growth plates.
B. Broad chest: This is a feature of Marfan's syndrome, characterized by connective tissue abnormalities, not Turner's syndrome.
C. Gynecomastia: As mentioned earlier, gynecomastia is caused by excess estrogen production, while Turner's syndrome results in insufficient estrogen production.

**Clinical Pearl:** Turner's syndrome is a crucial diagnosis in pediatric and adult female patients with short stature, webbed neck, and other associated features. Comprehensive evaluation for the presence of Turner's syndrome should include karyotyping to identify the monosomy X and assess the hormonal profile including estrogen levels.

**Correct Answer:** D. Broad chest (B)

**Core Concept:** Broad chest is a feature of Marfan's syndrome, a genetic disorder characterized by connective tissue abnormalities. It is caused by mutations in the FBN1 gene, encoding fibrillin-1 protein, which participates in the synthesis of microfibrils in the extracellular matrix.

**Why Each Wrong Option is Incorrect:**

A. Short stature: Turner's syndrome presents with short stature due to impaired growth hormone secretion and underdeveloped growth plates.
B. Broad chest: This feature is present in Marfan's syndrome, not Turner's syndrome.
C. Gynecomastia: As mentioned earlier, gynecomastia is caused by excess estrogen production, while Turner's syndrome results in insufficient estrogen production.