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Human Genetics has many areas of expertise, with specialists in each area. This course will focus on four areas, classical or Mendelian genetics, diseases where major effects are from a single locus, multifactorial inheritance, continuous traits (height, intelligence, etc.) and discontinuous traits (pyloric stenosis, cleft palate, etc.) where several genes plus environmental factors are involved, cytogenetics, diseases involving chromosomal abnormalities, and mathematical genetics, including population genetics, linkage, and mapping. Molecular genetics, the most rapidly developing of the genetic fields will be covered in the lecture portion of BMS 655, Human Genetics. Even at the basic level molecular genetics is changing too rapidly to be included in this computer-based course. All of these areas of human genetics interact and impact upon one another, but there is probably no individual who can work at the cutting edge of all fields - there is no true human geneticist.

Genetics, by its very nature, often involves the study of abnormality. But abnormality is a matter of definition. Sometimes the population cannot be divided into two discrete groups, but shows continuous variation. Intelligence, as measured by some test, is one such trait. In a population the distribution of intelligence follows a bell-shaped or Gaussian curve of continuous variation. Yet, we divide the population into groups (mentally challenged, normal, genius). Other traits show nearly discontinuous variation, disease or nondisease. But when we look closely even these individuals show some continuity, from severely affected, to mildly affected, to normal. Genetic abnormality therefore should be thought of as a continuum.