ABSTRACT
On the twenty-fi rst day of August 1990, our third grandchild is born and George’s chromosomes show up in our mailbox — rather pictures of them do, carefully arranged in neat rows to form his karyotype. Thus two important secrets are revealed in a single day: The child turns out to be a girl-46XX as far as anyone knows; George turns out to be a mosaic-38XY/39XXY as the Serology Lab tells us for sure.
