TYS question

Just to address an interesting (and almost depressing) TYS question raised

D01Q20

This is one weird question that will not make sense unless you know the background of it - yet has never been taught - one of those funny questions that Cambridge throw.

Thus, despite the intro of the question, BRCA 1 can be carried by the male without the manifestation of the disease. Why? Because while it is NOT sex-linked, the allele regulate production of estrogen and progestrone (http://www.sciencedaily.com/releases/2006/01/060126192801.htm) which are found in typically high amounts in the females, as normal chemical constituents. Thus a reduction in their production will affect the female compared to the males who already have low amount of the hormones. =)