Does House know about Thirteen's CAG test results?

This crossed my mind too. Although I'm not sure if House knows her CAG results, he was present when she stated she only has "8-10" years during the episode "Last Resort"...so he does know her timeframe. This being said, the 8-10 years is an estimate, CAG results make up only about 40% of a determinant of onset and progression. Furthermore, it is possible that when stating that she had 8-10 years, 13 may not have been talking about how much longer she would live, but how much longer she perceived that she would have a significant 'Quality of life'. Symptoms take a while to progress, and she may figure that within 8-10 years, she will be so severely cognitively, psychiatrically, and physically affected, that she will no longer have any autonomy or understanding, and that her personality will be significantly altered.

She could be referring to her lifespan though. It sounds like her mother's illness progressed very quickly after initial onset...and hers is therefore likely to follow a similar pattern. --AND, last night, it looks like we saw a symptom when her hand tremored...so it looks like initial onset has occurred.

I'm very interested to see how they proceed with this, and how Huntington's is portrayed on this show!