Which sex chromosome genotype is associated with Jacob syndrome?

• A. 47,XYY
• B. 47,XXY
• C. 47,XXX
• D. 45,X

Answer: (A)

Verified step by step guidance

1. Understand that Jacob syndrome is a chromosomal disorder involving the sex chromosomes, specifically an abnormal number of Y chromosomes in males.
2. Recall the normal male karyotype is 46,XY and the normal female karyotype is 46,XX.
3. Identify that Jacob syndrome is characterized by the presence of an extra Y chromosome, leading to a total of 47 chromosomes.
4. Recognize that the notation for Jacob syndrome is 47,XYY, indicating one X chromosome and two Y chromosomes.
5. Compare the given options to this notation to determine that 47,XYY corresponds to Jacob syndrome.