It is important that individuals feel that their own personal information is private and treated as such, with full respect for confidentiality. However, some information about the family can be regarded as belonging to the family as a whole. Consanguinity, or marriage between close relatives, is a common and important issue in genetic counselling. An accurate idea of how individuals are related is important in all genetic counselling, regardless of the presence or absence of consanguinity, but when a marriage between close relatives is being considered it becomes essential. It is helpful in genetic counselling to be aware of the legal aspects of consanguineous marriages because many couples have unspoken fears about the legality of a relationship as well as the genetic risks. It is possible for a couple to be closely related simply because they are both members of an inbred population which has many of its genes in common.