Conductive hearing loss and malformed low-set ears, as a possible recessive syndrome.

More than 50 phenotypically distinct forms of hereditary deafness have been found in man (Konigsmark and McKusick, 1966; Procter and Procter, 1967).On the basis of associated defects caused by the same gene, these can be separated into 10 different groups.These groups include: deafness associated with integumentary system disease (Robinson, Miller, and Bensimon, 1962), heart disease (Fraser, Froggatt, and James, 1964), skeletal disease (Forney, Robinson, and Pascoe, 1966), eye disease (Alstrom et al., 1959), nervous system disease (Matthews, 1950), renal disease (Braun and Bayer, 1962), thyroid disease (Batsakis and Nishiyama, 1962), external ear malformations (Fourman and Fourman, 1955; Wildervanck, 1962), as well as deafness with no associated defects, and hereditary deafness with other associations.A Mennonite group has been found to offer an excellent opportunity for the study of some reces- sive hereditary diseases, for two reasons: excellent family records are available and the rate of consan- guineous marriages is high.The two interrelated families described here were found in a health survey of conservative Mennonites in Lancaster County, Pennsylvania.In Family I, 2 of 8 children were affected with malformed low-set ears and conductive hearing loss, while in Family II, 3 of 12 living sibs were similarly affected.Though two types of external ear deformities and hearing loss have been reported (Fourman and Fourman, 1955; Wildervanck, 1962), the deformities are quite different from those in the two branches of this family.The affected children recorded here prob- ably have a heretofore undescribed type of familial