The family history has long been an intrinsic part of the evaluation of a new patient. While family history is often synonymous these days with genetic history, its origins may date to a time when communicable diseases were much more common, hence the persistent admonition to medical students to ask whether anyone in the family has had tuberculosis. However, as the spectrum of morbidity in developed countries has changed,1,2 so too has the primary purpose of the family history. Today, that evolution continues, driven in large part by burgeoning knowledge about human and medical genetics.
See also pp 1242, 1251, 1262, and 1268.
Until recently, much of the focus of medical genetics has been on rare disorders.3,4 For common disorders, causation was either seemingly easy to ascribe (eg, infectious diseases) or complex (eg, atherosclerosis and cancer), but in neither case considered genetic.
However, during the past decade, increasing