Characterization
Thirteen is reluctant to reveal information about herself. The season four finale reveals she has the dominant mutation for Huntington's, the disease from which her mother died. In "Lucky Thirteen", Thirteen says that her Huntington's is more aggressive, greatly decreasing her life expectancy and hastening the onset of symptoms. She exhibits self-destructive behavior, using recreational drugs and having repeated one-night stands. House fires her for recklessness, but eventually rehires her. She later ceases to behave self-destructively, agreeing to participate in a Huntington's Disease drug trial.
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