TY - JOUR T1 - <em>VSX2</em> in microphthalmia: a novel splice site mutation producing a severe microphthalmia phenotype JF - British Journal of Ophthalmology JO - Br J Ophthalmol SP - 386 LP - 388 DO - 10.1136/bjo.2009.159996 VL - 94 IS - 3 AU - Emma M M Burkitt Wright AU - Rahat Perveen AU - Naomi Bowers AU - Simon Ramsden AU - Emma McCann AU - Mary O'Driscoll AU - I Chris Lloyd AU - Jill Clayton-Smith AU - Graeme C M Black Y1 - 2010/03/01 UR - http://bjo.bmj.com/content/94/3/386.abstract N2 - Microphthalmia shows great genetic and clinical heterogeneity, whether as part of a syndrome or an isolated ocular phenotype. Chromosomal or single-gene disorders and teratogens may all cause microphthalmia. Associated syndromic features include cardiac problems, clefting, microcephaly and learning disabilities.1 Microphthalmia is frequently bilateral, but commonly asymmetrical in severity.Homozygous mutations in VSX2/CHX10 have been demonstrated in human and murine microphthalmia.2 3 VSX2 is thought to act principally as a repressor of transcription, particularly of the genes encoding cyclin-dependent kinase inhibitor (p27kip1) and microphthalmia transcription factor (MITF).4 These repressive roles enable cell proliferation by preventing retinal progenitor cells from exiting the cell cycle, and by maintaining neuroretinal cell identity. Loss of these functions therefore causes failures in eye development. Other genes implicated in microphthalmia include SOX2, PAX6, sonic hedgehog (SHH), RAX, OTX2, CRYBA … ER -