External Auditory Canal, Bilateral Atresia Of, With Congenital Vertical Talus

Clinical Features

Among the descendants of a reportedly affected grandfather, Rasmussen et al. (1979) observed congenital bilateral symmetric subtotal atresia of the external auditory canal. Four of the 6 affected descendants had bilateral foot anomalies; 2 affected cousins had congenital vertical talus. All 3 affected males in the third generation had increased interocular distance, although not ocular hypertelorism. Rasmussen et al. (1979) concluded that the full syndrome consisted of atresia of the auditory canal, vertical talus, or possibly other bilateral foot deformity, and increased interocular distance. Short fifth fingers, bilateral single transverse palmar creases, pyloric stenosis, and congenital exotropia were other findings. The presumably affected grandfather had 3 affected daughters and a normal daughter and a normal son. Two of the affected daughters had affected sons. There was no instance of male-to-male transmission.

Julia et al. (2002) reported the case of a girl with external auditory canal atresia and congenital vertical talus. She was born to nonconsanguineous parents after a pregnancy complicated by hydramnios and breech presentation. In addition to the above findings, she also had congenital hip dislocation, umbilical hernia, epicanthal folds, convergent strabismus, low-set nasal bridge, mild hypoplasia of the alae nasi, abnormal external ears with hypoplastic lobes and overfolded helices, dysplastic dental enamel, low implantation of thumbs, and valgus foot deformation. Mental development and karyotype were normal. Audiologic examination showed bilateral conductive deafness with a 60 dB threshold, and CT scan confirmed the bilateral atresia of the external auditory canals. Julia et al. (2002) proposed the designation Rasmussen syndrome for this disorder.

Feenstra et al. (2011) described a sporadic case and a mother and 2 sons with 18q22.3-q23 microdeletions (601808), noting that the phenotype in the mother and sons closely resembled that of 3 males and 3 females in a family with bilateral atresia of the external auditory canal and congenital vertical talus described by Rasmussen et al. (1979).