Question

An abnormal human male phenotype involving an extra Y-chromosome (XYY) is a case of

• A. Edward's syndrome
• B. Jacob syndrome
• C. Intersex
• D. Down's syndrome

Answer 1

The correct option is B Jacob syndrome

• Edwards' syndrome is also called as trisomy 18. It is a genetic disorder in which there is one extra copy of chromosome 18. Symptoms include low birth weight, abnormal shape of the head.
• Jacob syndrome is a genetic disorder in which male has one extra copy of Y chromosome. His genotype is XYY. Symptoms include learning disabilities, impulsiveness.
• Intersex is a phenomenon in which an individual contains different reproductive or sexual anatomy than normal male or female.
• Down's syndrome is also called as trisome 21. It is a genetic disorder in which there is one extra copy of chromosome 21. Symptoms include developmental delay, upward slanting eyes, short neck.

Thus, the correct answer is 'Jacob syndrome.'