Question

Klinefelter’s syndrome results from

• A. XX egg and Y from sperm
• B. XX egg and XY sperm
• C. X egg and XY sperm
• D. Both (a) and (c)

Answer 1

Answer: (D)

Both options (a) and (c) are correct. This can be explained as In klinefelter’s syndrome, the sex chromosomes genotype is $XXY$, i.e. there is one extra $X$-chromosome. This extra $X$ can come in two conditions, when there is non-disjunction in egg, i.e. $XX$ egg and $Y$ sperm and where is non-disjunction in sperm, i.e. $X$ egg and $XY$ sperm.