Genetic disease since 1945.

Although hereditary disease has been recognized for centuries, only recently has it become the prevailing explanation for numerous human pathologies. Before the 1970s, physicians saw genetic disease as rare and irrelevant to clinical care. But, by the 1990s, genes seemed to be critical factors in virtually all human disease. Here I explore some perspectives on how and why this happened, by looking at two genetic diseases--familial dysautonomia and phenylketonuria.