Which neurotransmitters are possibly affected by huntington's disease?

Acetylcholine/GABA: There are specific decreases in acetylcholine and gaba, which in turn affect the activity of the neurotransmitter dopamine. Interestingly, this is the exact opposite of parkinson disease.

Perhaps several: This autosomal dominant disorder results in a mutation of chromosome 4 producing a misfolded protein, huntingtin, which deposits in cells affecting fnctn. Since neuroleptics work by blocking Dopamine receptors, and can help chorea, and since the striatum is involved, probably both Dopamine and glutamine are affected, at the least.