An analysis of the human genetics content of 13 general biology textbooks.

Professionals in genetics, medicine, and biology education have in recent years called for placing greater emphasis on human genetics in the education of the nation's citizenry. Since a large collegiate audience for such education is found in the general biology classroom, we elected to analyze 13 current and widely used general biology textbooks to determine their human genetics content. The analyses revealed that from 6.68 to 15.51 percent of the books' pages were devoted to genetics, but only 0.75 to 3.44 percent of the pages dealt specifically with human genetics. The number of human genetic traits discussed in the books ranged from four to 24, with a mean of 15.77. Nine different chromosome aberrations were cited, with Down, Klinefelter, and Turner syndromes being mentioned most often. Twenty autosomal dominant, fifteen autosomal recessive, and seven X-linked traits were used as examples in the various textbooks. Most frequently cited single-gene conditions were the ABO blood groups, sickle cell anemia, phenylketonuria, hemophilia, and red/green colorblindness. The books varied considerably in the emphasis given to social applications of medical genetics. Based on the findings of this study, we offer several recommendations for the improvement of the human genetics content of general biology textbooks and courses.