Cabot et al. (1999) reported a large French family in which 12 individuals spanning 4 generations had idiopathic congenital nystagmus. There were 7 affected females and 5 affected males. Nystagmus was noted at birth or in the first ... Cabot et al. (1999) reported a large French family in which 12 individuals spanning 4 generations had idiopathic congenital nystagmus. There were 7 affected females and 5 affected males. Nystagmus was noted at birth or in the first year of life, and there were no other abnormalities of the visual or neural visual pathways as shown by detailed studies. The pedigree pattern was consistent with X-linked dominant inheritance with incomplete penetrance.