RAX gene

Overview

Gene (OMIM No.)	RAX (#601881)
Function of gene/protein	Vital in early eye development, particularly in retinal cells Regulates other genes by binding to specific DNA regions (transcription factor)
Clinical phenotype (OMIM phenotype no.)	Microphthalmia, isolated 3 (#611038)
Inheritance	Autosomal recessive
Ocular features	Microphthalmia, anophthalmia, coloboma (MAC) spectrum (usually bilateral) Ankyloblepharon Sclerocornea
Systemic features	Intellectual disability has been reported
Key investigations	B-scan USS to measure axial length to document microphthalmia Electrophysiology MRI brain and orbit Developmental assessment may be indicated with learning difficulties
Molecular diagnosis	Next generation sequencing Targeted gene panels (MAC) Whole genome sequencing
Management	Ocular Management of MAC
Therapies under research	None at present
Further information	OMIM

Mathers PH, Grinberg A, Mahon KA, Jamrich M. The Rx homeobox gene is essential for vertebrate eye development. Nature
Chassaing N, Causse A, Vigouroux A, et al. Molecular findings and clinical data in a cohort of 150 patients with anophthalmia/microphthalmia. Clin Genet. 2014;86(4):326‐334
Abouzeid H, Youssef MA, Bayoumi N, et al. RAX and anophthalmia in humans: evidence of brain anomalies. Mol Vis. 2012;18:1449‐1456
Lequeux L, Rio M, Vigouroux A, et al. Confirmation of RAX gene involvement in human anophthalmia. Clin Genet. 2008;74(4):392‐395
Voronina VA, Kozhemyakina EA, O’Kernick CM, et al. Mutations in the human RAX homeobox gene in a patient with anophthalmia and sclerocornea. Hum Mol Genet. 2004;13(3):315‐322

Updated on November 30, 2020