Table 5.

Cognitive factor associations with NKCC1 rs3087889^a

	Healthy controls	SCZ	Family
Verbal memory	0.901 (N = 409)	0.519 (N = 302)	0.041 (N = 91)
N-back	0.006* (N = 369)	0.674 (N = 181)	0.061 (N = 60)
Visual memory	0.366 (N = 271)	0.827 (N = 298)	0.004* (N = 91)
Processing speed	0.119 (N = 408)	0.671 (N = 302)	0.018 (N = 90)
Card sorting	0.155 (N = 399)	0.507 (N = 295)	0.028 (N = 89)
Digit span	0.350 (N = 288)	0.838 (N = 301)	0.035 (N = 91)
g	0.030 (N = 391)	0.548 (N = 299)	0.678 (N = 89)

^aNKCC1 rs3087889 A allele was associated with working memory (N = 369) and g (N = 391) in healthy subjects. Although not associated with cognitive measures in schizophrenic subjects per se, family-based association showed that this SNP associated with between-sibling differences in most factors to some extent.

*p values survive minimal correction for number of factor scores tabulated (n = 7, p < 0.007); however, they would not survive a more rigorous correction for number of scores and grouping variables (n = 21, p < 0.002).