Table 1.

Type 1 error rate for the CMC and burden tests before and after correction by principal component (PCA) and genomic control (GC), based on 1,000 cases and 1,000 controls.

Cases that are of African Ancestry, %	Region size kb	Before correction		After correction (PCA)		After correction (GC)
		CMC	Burden	CMC	Burden	CMC	Burden
50%	1	0.064	0.068	0.064	0.058	0.064	0.068
	10	0.045	0.056	0.055	0.060	0.045	0.056
	50	0.064	0.075	0.058	0.062	0.064	0.075
90%	1	0.444	0.426	0.046	0.046	0	0
	10	0.580	0.610	0.060	0.060	0	0
	50	0.240	0.670	0.060	0.097	0	0

Simulations assume 50% of controls have African ancestry.