Table 4.

Heritability estimates of tic factors and tic severity with age and sex as covariates, and with and without other factors as co-variates

Number of factors	h2r	SE	p	kurtosis	covariate(s)
Factor 1 (Complex)	0.21	0.06	0.0006	0.56	age*, sex, factor 2, factor 3
Factor 1 (Complex)	0.18	0.06	0.003	0.67	age, sex*
Factor 2 (Body)	0.004	0.07	0.48	−0.2	age*, sex*, factor 1, factor 3
Factor 2 (Body)	0	na	0.5	−0.27	age, sex*
Factor 3 (Head)	0.25	0.11	0.02	0.11	age, sex*, factor 1, factor 2
Factor 3 (Head)	0.18	0.09	0.03	−0.28	age, sex*
Tic Severity (YGTSS)	0.19	0.09	0.027	−0.43	age, sex*

^*Covariates did not contribute significantly to the proportion of variance, and was removed from the final model.