Heterotopic ciliary epithelial differentiation in a patient with trisomy 13.

A premature infant was born with congenital anomalies suggestive of trisomy 13, confirmed by karyotype analysis. Pathologic examination of the eyes revealed typical features of trisomy 13, including microphthalmos, extensive colobomata, and retinal dysplasia. A heterotopic ciliary body had also developed in the posterior segment of the left eye in the region of the posterior coloboma. The development of a well-formed ciliary body in the posterior segment of the eye questions the hypothesis that physical contact between the lens primordium and neuroepithelium is required for ciliary body development.