Trisomy 18.  A temporal bone report.
Since Edwards first described the trisomy 17-18 syndrome in 1960, the findings in the temporal bones of only four patients with this condition have been reported.  They varied widely, ranging from a normal temporal bone, to severe malformations of both the middle and inner ear structures.  This study describes the temporal bone findings in a patient with this syndrome.  Many of the abnormalities described previously were present as well as the following unreported findings: complete bony atresia of the external canal, an aberrant tensor tympani muscle that did not insert into the malleus but rather attached to a dehiscent area in the Fallopian canal, wide short utricular and saccular ducts, and a widely patent cochlear aqueduct.  There was also a developmental arrest of the membranous structures within the cochlea that probably occurred during the 12th week of fetal life.
D001344:Autopsy; D002902:Chromosomes, Human, 16-18; D003051:Cochlea / Q000473:pathology; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D012665:Semicircular Canals / Q000473:pathology; D013701:Temporal Bone / Q000473:pathology; D014314:Trisomy; D014722:Vestibule, Labyrinth / Q000473:pathology