An underdeveloped or small uterus is associated with which chromosomal condition?

• A. Down Syndrome
• B. Klinefelter Syndrome
• C. Turner Syndrome (45 XO)
• D. Triple X Syndrome

Answer: (C)

A small or underdeveloped uterus points to estrogen deficiency from gonadal dysgenesis, most characteristically seen in Turner syndrome (45,XO). In Turner, the ovaries are often streaks and fail to produce normal amounts of estrogen. Since estrogen drives uterine growth during puberty, insufficient estrogen leads to a hypoplastic or small uterus.

The other conditions don’t typically cause this uterine finding. Down syndrome is a trisomy 21 condition with generally normal ovarian function and normal uterine development if female. Klinefelter syndrome is a male condition (46,XY with an extra X) and does not develop a uterus. Triple X syndrome (47,XXX) is a female chromosomal pattern usually with normal ovarian function and a uterus of normal size.