Ellwood et al. (1968) reported 2 sibships: the first, with first-cousin parents, included a brother and sister with bilateral anotia and meatal atresia; the other included 2 brothers, one with unilateral microtia and bilateral meatal atresia and the ... Ellwood et al. (1968) reported 2 sibships: the first, with first-cousin parents, included a brother and sister with bilateral anotia and meatal atresia; the other included 2 brothers, one with unilateral microtia and bilateral meatal atresia and the other with unilateral microtia and meatal atresia. Dar and Winter (1973) reported a family, and Konigsmark et al. (1972) observed affected sibs. Strisciuglio et al. (1986) described a sibship of 3 in which all were affected with different degrees of severity. Guizar-Vazquez et al. (1978) described a mother with microtia and meatal atresia on the right, whose son had the same combination on the left. Both had some macrostomia and facial asymmetry, but features of Goldenhar syndrome (164210) and Treacher Collins syndrome (154500) were missing. Zankl and Zang (1979) supported irregular dominant (presumably autosomal) inheritance on the basis of a family with 5 affected members in 4 sibships of 2 generations. Sanchez-Corona et al. (1982) studied patients with microtia and conductive hearing loss, which appeared to be inherited as an autosomal dominant. Oliveira et al. (1989) reported 2 sibs with almost identical anomalies of the external and middle ear and no other congenital defects. Their father had similar malformations, but no one else in this large sibship presented ear malformations; the defects were also absent in 2 previous generations. The authors suggested that these congenital malformations could have appeared by spontaneous mutation in the father and been transmitted as an autosomal dominant trait to his children. Orstavik et al. (1990) described right-sided external ear malformations and conductive hearing loss in a grandfather, his daughter, and granddaughter. The grandfather and granddaughter had microtia and meatal atresia, whereas the daughter had a normal outer ear except for a narrow meatus and auricular appendages. Gupta and Patton (1995) described a large 5-generation kindred with autosomal dominant inheritance of congenital microtia and auditory meatal atresia with conductive deafness. One of the affected members had renal cysts, suggesting that this might be a variant of the branchiootorenal (BOR) syndrome (113650); however, the authors maintained that the dominant malformation syndrome in their patients was a distinct entity. Gupta and Patton (1995) found previous reports of 9 families in which autosomal recessive inheritance was implied in 4 and autosomal dominant inheritance in 5. Alasti and Van Camp (2009) reviewed the genetics of microtia and associated syndromes and discussed their clinical aspects in relation to the causative genes. They stated that the estimated prevalence of microtia is 0.8 to 4.2 per 10,000 births, that it is more common in males, and that it can have a genetic or environmental predisposition.