Question

Most common cause of mental retardation (congenital) in male children is

• A. Jacob syndrome or super males
• B. Down's syndrome
• C. Klinefelter's syndrome
• D. Phenylketonuria

Answer 1

The correct option is B Down's syndrome

• The condition where XYY genome is present they are known as Jacob's syndrome which leads to the formation of super male.
• Downs syndrome is a genetic disorder due to the presence of an extra copy of a chromosome that leads to abnormal growth and mental retardation.
• Klinefelter's syndrome is mainly caused due to the two or more X chromosomes. The genome is 47+XXY. The main symptom is sterility.
• Phenylketonuria is a defect in the amino acid phenylketone that leads to mental retardation or death of the child in weeks.

Thus, the correct answer is option B.