Deafness, Conductive, With Malformed External Ear

Clinical Features

In 2 sibships in a Mennonite isolate, Mengel et al. (1969) observed 6 persons with conductive deafness and malformed, low-set external ears. The 4 parents shared a common ancestral couple. At operation, malformation of the ossicles was demonstrated in the middle ear. Mental retardation and hypogonadism may be additional features. Cantu et al. (1978) observed a brother and 2 sisters with this disorder. The parents were normal and related as third cousins.

Megarbane et al. (2005) described 2 sisters, offspring of healthy consanguineous Lebanese parents, who had developmental delay, short stature, microcephaly, abnormal ears, short neck, defects of the auditory canal and middle ear, and nonprogressive hearing impairment. One sister also had esophageal atresia and the other, cleft palate. The authors noted similarities to the patients previously described by Mengel et al. (1969) and Cantu et al. (1978), but in light of the differences exhibited by their patients (microcephaly and facial abnormalities), they speculated that the latter might represent a new syndrome.

Inheritance

Consanguinity and affected sibs suggest autosomal recessive inheritance of this disorder (Mengel et al., 1969).