Trembling chin--a report of this inheritable dominant character in a four-generation Canadian family.

Trembling chin is an unusual, benign, dominant trait. We describe the condition in a four-generation Canadian family. Investigations, which included E.E.G., electromyograph and facial nerve conductance studies on affected and unaffected individuals, were normal. Premature hearing loss, present in all affected members of this family over age 50, strongly suggests an association of trembling chin with otosclerosis. The merits of early diagnosis and preventive treatment for otosclerosis in persons affected by trembling chin are discussed.