HISTOPATHOLOGY AND MOLECULAR CYTOGENETICS OF A CORNEAL OPACITY ASSOCIATED WITH THE TRISOMY-8 MOSAIC SYNDROME (46,XY 47,XY,+8)/

The trisomy 8 mosaic syndrome (Tr8MS), karyotype 46,XY/47,XY, +8, is a rare multisystem disorder that may be associated with corneal opacity . We report the case of a dysmorphic infant with multiple congenital a bnormalities referred to our unit with a congenital corneal opacity. S ubsequent chromosomal analysis of peripheral leucocytes demonstrated c onstitutional Tr8MS. At 4 years of age, lamellar keratoplasty was perf ormed. Histological examination confirmed the lesion to be consistent with a corneal choristoma. Cytogenetic studies using in situ hybridisa tion techniques showed the presence of trisomic cells in cell culture derived from the tissue in higher proportion (92%) than in the blood ( 44%). Amplification of the c-myc oncogene on chromosome-8 could not be detected in cells cultured from the corneal lesion. Although not proo f, these findings lend support to the concept of the corneal lesion re presenting a focus of viable trisomic cells rather than an inflammator y response to a nidus of effete cells.