Table 1.

Demographics for the NTRK1-T carriers versus non-carriers

Genotypes	T carriers	T non-carriers
Subjects (n)	31	360
Sex	16 M, 15 F	126 M, 234 F
Agea	23.8 ± 2.5	23.6 ± 2.2
IQ test scores	29	348
Performance IQa	119.9 ± 14.9	113.7 ± 15.6
Verbal IQa	114.8 ± 10.7	111.8 ± 10.8
Full-scale IQa	118.6 ± 11.4	113.8 ± 12.5

Sex, age, and IQ scores were not significantly different between genotype groups (p > 0.05). After removing one twin from each MZ pair, we used a two-tailed t test to evaluate group differences in age and a χ² test to evaluate group differences in sex. In all subjects, we used multiple regression to evaluate group differences in IQ while controlling for age, sex, and kinship. M, Male; F, female.

^aValues are mean ± SD.