Ricki Lewis

“Anticipation .. is keepin’ me waitin’,” sings Carly Simon in her song made famous in a ketchup commercial. But “anticipation” in the genetic sense is just the opposite of Carly’s croon – it means a disease that begins earlier with each generation.

Doctors once blamed patients for anticipation, as if people with sick older relatives could worry themselves into suffering similarly. Then, in 1991, discovery of a new type of mutation explained the curious worsening of fragile X syndrome: an expanding triplet repeat.  Read More 

Let me get this straight: The human Y chromosome has barely changed from that of a rhesus macaque, a monkey from whom we parted ways some 25 million years ago, and that’s good news? I suppose compared to disappearing, it is.

For several editions now, my human genetics textbook has run an “In Their Own Words” essay in which MIT’s David Page, protector of the Y, has defended the measly male chromosome against charges from Jennifer A. Marshall-Graves, of Australian National University, that it is disappearing. She helpfully points out in my book, “You can lack a Y and not be dead, just female,” then goes on to call the Y “a pathetic little chromosome that has few genes interposed with lots of junk.”  Read More