No other chromosome would pass intact from generation to generation under these circumstances. Transmission of the priestly Y chromosome could be tested by the methods of molecular genetics. And in fact groups of researchers based in Israel, Canada, England and the USA recently collected cells from Jewish priests, and from other male Jews, for just such a test. Among 68 subjects who identified themselves as member of the priestly family, researchers did in fact observe DNA sequences that were uniquely different from those of 120 male members of the Jewish lay population. In a later paper describing a similar study of DNA from 306 Jewish males, the origin of the Cohen Y chromosome was traced to a period about 3200 years ago.
Affected embryos have the XY chromosomes of a normal male.
The testes develop, and they produce normal amounts of the male hormone, testosterone. But the hormone is not properly metabolized, and as a result, the penis and scrotum are not formed. The body parts that normally give rise to penis and scrotum give rise instead to structures that may resemble very closely, the external genital organs of a normal female. Because they look very much like little girls, patients with this condition often are raised initially as females. But there is an extraordinary turn of events at puberty.