染色体異常（46，XY，t（5；6），ins（7））による中耳奇形の1症例

Ossicular Malformation accompanied by Chromosomal Aberration: Report of a Case

I．はじめに

　中耳奇形をはじめ先天奇形の成因は複雑である。奇形の原因としては遺伝子，染色体，胎生環境（薬剤，感染），あるいは遺伝的要因と環境要因の相互作用などが挙げられる。今回私たちは染色体異常が認められた外耳・中耳奇形および顎，顔面の発育不全，精神発達遅滞を呈する1症例を経験したので，ここに報告する。

An 8-year-old boy presented a conductive hearing loss in both ears with microtia, stenosis of the external ear canals and micrognathia. At thetime of ear surgery, multifocal ossicular malformations were found, i.e. bony fixation of the head of the malleus, and discontinuity of the incudostapedial joint, in addition to abnormal shape of all the ossicles. Chromosomal analysis revealed translocation between No. 5 and No. 6 and insertion of No. 7 autosomes. It is recommended that the chromosomal pattern should be checked in patients with ossicular malformation, especially when craniofacial abnormality is present.