**Question:** Which one of the following is NOT a feature of Turner's syndrome –

A. Short stature
B. Monosomy X (45,X karyotype)
C. Oligohydramnios
D. Congenital heart defects

**Correct Answer:** C. Oligohydramnios

**Core Concept:** Turner's syndrome is a genetic disorder that primarily affects females due to the presence of a partial or complete absence of one of the two X chromosomes. The most common karyotype is 45,X. The clinical manifestations of Turner's syndrome can be broadly categorized into growth, skeletal, endocrine, and cardiovascular features.

**Why the Correct Answer is Right:** Oligohydramnios is characterized by reduced amniotic fluid volume, which can lead to developmental abnormalities during pregnancy. In Turner's syndrome, the primary features involve growth retardation, skeletal abnormalities, and cardiovascular issues, making oligohydramnios an unlikely manifestation.

**Why Each Wrong Option is Incorrect:**

**A. Short stature:** Turner's syndrome is characterized by short stature, making this a feature associated with the syndrome.

**B. Monosomy X (45,X karyotype):** Turner's syndrome is caused by the presence of a partial or complete absence of one X chromosome, making this an essential feature of the syndrome.

**D. Congenital heart defects:** Turner's syndrome is associated with a high prevalence of congenital heart defects, making this a common manifestation of the syndrome.

**Clinical Pearl:** Turner's syndrome is a crucial topic for medical students, particularly for those studying obstetrics, pediatrics, and genetics. Recognizing Turner's syndrome is crucial for early diagnosis, management, and counseling of affected individuals and their families.