My first Fragile X case was in graduate school in 1984. A young man, about to be married, had a brother with Fragile X syndrome, and he wanted genetic counseling prior to his wedding. The first rumblings of "transmitting males" were arising so we imparted on him a small risk to be some sort of carrier, with no symptoms, and to be at risk for grandchildren with FXS. Even then, that was pretty advanced stuff, straying from the usual X-linked inheritance that previously reassured unaffected males that they could not pass on the disorder.