Thirteen says that it was Huntington's chorea, meaning that she has a 50% chance of also carrying the mutation that leads to the disease, which is what caused her to become upset when she dropped her files and when her hand shook.
Thirteen says that it was Huntington's chorea, meaning that she has a 50% chance of also carrying the mutation that leads to the disease, although she refuses to be tested. Her ignorance of her Huntington's status is what caused her to become upset when she dropped her files and when her hand shook.