SLEEP-WALKING IN TWINS

Abstract

To investigate the possibility of a hereditary predisposition to sleep-walking, the degree of concordance in monozygotic and dizygotic twins was compared. Monozygotic twins were concordant for the symptom six times as often as dizygotic twins (p=0·04)—a finding consistent with a genetic basis. The increased incidence of sleep-walking in the children when a parent had been a somnambulist also favours this view. Enuresis and persistent finger-sucking were commoner in the somnambulists than in the non-sleep-walkers; the prevalence of nail-biting was the same in these two groups.