RAX gene


Gene (OMIM No.)
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)
  • Autosomal recessive
Ocular features
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 diagnosisNext generation sequencing
  • Targeted gene panels (MAC)
  • Whole genome sequencing
Therapies under research
  • None at present
Further information

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  1.  Mathers PH, Grinberg A, Mahon KA, Jamrich M. The Rx homeobox gene is essential for vertebrate eye development. Nature
  2.  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
  3.  Abouzeid H, Youssef MA, Bayoumi N, et al. RAX and anophthalmia in humans: evidence of brain anomalies. Mol Vis. 2012;18:1449‐1456
  4.  Lequeux L, Rio M, Vigouroux A, et al. Confirmation of RAX gene involvement in human anophthalmia. Clin Genet. 2008;74(4):392‐395
  5.  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

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Updated on November 30, 2020
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