Recording a Family Medical History or Pedigree
A careful and detailed family health history is the basic prerequisite for any form of genetic counseling. It is essential to have detailed information about the proband’s relatives even when the proband himself is clearly suffering from a genetic disorder of which the mode of inheritance has, ostensibly, been established. In genetics, there is always the possibility that a particular family will prove to be an exception. For example, a genetic defect, generally considered as autosomal recessive, can in some cases be passed on as a dominant trait. This, of course, also demonstrates that the same clinical disease has a separate genetic cause. A detailed pedigree gives us the necessary basic information for all further genetic considerations. It simplifies matters for oneself and the potentially required geneticist if the pedigree is drawn up with the symbols in common usage, such as those given in Figures 2.1a, b.
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