Question

Which of the following sex chromosome aneuploidies results in phenotypically normal females who are taller than average?

Options

• XYY Syndrome (47, XYY)

• Turner's Syndrome (45, XO)

• Klinefelter's Syndrome (47, XXY)

• Triple X Syndrome (47, XXX)

Answer 1

Triple X Syndrome (47, XXX) results in phenotypically normal females with taller-than-average height. The incidence is approximately 1 in 1,000 female newborns. These individuals may have mild learning difficulties but are often fertile. The presence of an extra X chromosome does not typically produce severe clinical manifestations.