Dunno, wildbill, whether this is true or not.
For whatever it is worth, my youngest was born with this deep purple spot also.
When I questioned the doc about it, he called it the “Mongolian Bruise”, and said it related back to Ghengis Kahn (Jenjis Kahn to JFKerry types). My husband’s parents both have ancestors in Southern Italy, so possibly that is the link.
My ancestors are all from Scotland, Wales, etc...
http://www.uchicagokidshospital.org/online-library/content=P02691
Mongolian spots Mongolian spots are blue or purple-colored splotches on the baby’s lower back and buttocks. Over 80 percent of African-American, Asian, and Indian babies have Mongolian spots, but they occur in dark-skinned babies of all races. The spots are caused by a concentration of pigmented cells. They usually disappear in the first four years of life.