Andrew J. Hogan

Dissertation: "Chromosomes in the Clinic: The Visual Localization of Syndromes in the Human Genome, 1969-Present"    (Advisor: Prof. Susan Lindee)

My research looks at the history of medical genetics, with a particular interest in the role of chromosomal analysis in the delineation, diagnosis, and understanding of syndromes.  I explore the often drawn-out process by which clinical disorders become associated with specific, microscopically visible chromosomal abnormalities.  During the 1970s and 1980s, medical geneticists associated a large number of clinical syndromes with particular chromosomal regions and abnormalities, such as visible deletions, duplications, and translocations of genetic material.  The diagnostic value of such chromosomal aberrations varied however, as certain markers were inconsistently visible, or seen in patients who looked quite different in the clinic.  Such complications encouraged medical geneticists to move beyond simply associating syndromes with structural chromosomal abnormalities, and into examining the functional role of these aberrations in clinical outcomes.  Using historical case studies of various genetic disorders including Fragile X, Prader-Willi, and DiGeorge syndromes, I explore the central role of chromosomes as visual and conceptual tools in clinical research, and human genetics more broadly.  Chromosomes offer a unique opportunity to view the human genome in its entirety, and analyze its structural, evolutionary, and functional characteristics.  Indeed, well before the era of large-scale DNA sequencing, chromosomal analysis offered geneticists valuable insights into the complex and multi-dimensional workings of the human genome.