During the first cellular division called meiosis I, the chromosomal pairs are separated.

第一次细胞分裂，即第一次减数分裂后，配对的同源染色体分离。

In Klinefelter syndrome, the sex chromosome pairs which is either XX or XY don't separate in meiosis I in the male or female germ cell and this resulted in two gametes with a pair of X chromosomes and two gametes without X chromosomes.

Klinefelter综合征中，配对的XX或XY性染色体对在父亲或母亲的第一次减数分裂中没有分离，从而产生了两个有两条X染色体的配子以及两个没有X染色体的配子。