Serum PON1 activity in the examined HD patients (median 101.0 U/L, range 27.7–212.9 U/L) places within the broad range of values observed in HD groups by other authors (58.0 ± 36.7 U/L8–258.3 ± 42.51 U/L on NaCl-stimulation55). This evidence concerns the gene PON1 and Huntington disease.