Is there a duty to share genetic information?

A number of prominent bioethicists, such as Parker, Lucassen and Knoppers, have called for the adoption of a system in which by default genetic information is shared among family members. This paper suggests that a main reason given in support of this call to share genetic information among family members is the idea that genetic information is essentially familial in nature. On examining this "familial nature of genetics'' argument, the paper shows that most genetic information is only shared in a weaker way among family members and does not necessarily lead to the actual manifestation of particular diseases. The upshot is that the idea that genetic information is familial in nature does not provide sufficient ground for moving towards a system in which by default genetic information is shared among family members.