MAPT and red-green color blindness: Additionally, H1o was associated with a significantly higher risk of PSP (OR = 2.60, P = 2 × 10−5), which is not overly divergent from the non-significant OR of 1.81 (P = 0.080) that we noted for CBD; the absence of a statistically significant association between MAPT H1o and risk of CBD in our study may be due to the less precise haplotype frequencies and lower power to detect associations that we had in comparison to our previous PSP study where the number of cases was greater than threefold higher.