What are the motifs in Mortal Fear by Greg Iles?

Desire is a recurring idea, though the various characters desire different things. In the case of Berkmann, the desires change over the course of his lifetime. As a young man, he fears being injured because of his disease but still apparently has normal sexual desires - though he is unable to fulfill those. He eventually discovers that he is most excited by a cadaver and later finds sexual fulfillment in the arms of a woman who was willing to lie still with him during their first encounter, effectively leading him to enjoy other types of sex.