Inheritance in the etiology of convergent squint.

From a study of 195 unselected cases of idiopathic squint, the authors distinguish three types of squint (simple, accommodative, and with amblyopia). Both sexes are equally affected, the age of onset is later in accommodative squint than in the other two types. The percentage of familial cases (65.4%) is comparable whatever the type of squint involved, the sex of the subjects or the age of onset. The family study and the complex segregation studies show that the hypothesis of dominant autosomal inheritance with incomplete penetrance is the most probable for the three types, but they do not affirm that three distinct entities are involved.