The disorder where an extra sex chromosome in the 23rd pair results in XXY, producing a male with reduced masculine characteristics, such as enlarged breasts, obesity, and excessive height, is called:

Correct option is D

Explanation:

Klinefelter’s Syndrome (Correct):

• Cause: An extra X chromosome (XXY) in males.
• Characteristics: Reduced masculine features, enlarged breasts (gynecomastia), low testosterone levels, small testes, infertility, obesity, and excessive height.
• Occurrence: Affects approximately 1 in 500–1,000 male births.

Information Booster:

• Symptoms: Tall stature, gynecomastia, low energy levels, learning difficulties, and infertility.
• Treatment: Hormone therapy (testosterone replacement) and educational or social support.

Additional Information:

1. Phenylketonuria (PKU):
• A genetic metabolic disorder caused by the inability to break down phenylalanine.
• Leads to intellectual disabilities if untreated but does not involve chromosomal abnormalities.
2. Turner’s Syndrome:
• A chromosomal disorder affecting females, caused by the absence of one X chromosome (XO).
• Symptoms include short stature, infertility, and underdeveloped sexual characteristics.
3. Tay-Sachs Disorder:
• A rare genetic disorder causing the destruction of nerve cells in the brain and spinal cord.
• It does not involve chromosomal abnormalities or male-specific features.