A boy with Klinefelter syndrome (47, XXY) is born to a mother who is phenotypically normal and a father who has the X- linked skin condition called anhidrotic ectodermal dysplasia. The mother’s skin is completely normal with no signs of skin abnormality. In contrast, her son has patches of normal skin and patches of abnormal skin.
Which parent contributed the abnormal gamete, when did the meiotic mistake occur, and explain the son's skin phenotype?
a. The father must have contributed to the abnormal X-linked gene.
b. The mother must have contributed to the abnormal X-linked gene.
c. Both parents must have contributed to the abnormal X-linked gene.
d. The son's condition must be the consequence of a spontaneous mutation.