Case series: Pyramidal cataracts, intact irides and nystagmus from three novel PAX6 mutations

Bharesh K Chauhan; Anagha Medsinge; Matthew P Baumgartner; Hannah L Scanga; Smaragda Kamakari; Eva Gajdosova; Carlos J Camacho; Ken K Nischal

doi:10.1016/j.ajoc.2018.02.021

Case series: Pyramidal cataracts, intact irides and nystagmus from three novel PAX6 mutations

Am J Ophthalmol Case Rep. 2018 Feb 28:10:172-179. doi: 10.1016/j.ajoc.2018.02.021. eCollection 2018 Jun.

Authors

Bharesh K Chauhan^{1

2}, Anagha Medsinge¹, Matthew P Baumgartner³, Hannah L Scanga¹, Smaragda Kamakari⁴, Eva Gajdosova⁵, Carlos J Camacho³, Ken K Nischal^{1

2}

Affiliations

¹ UPMC Eye Center, Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA.
² Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.
³ Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, PA 15260, USA.
⁴ Ophthalmic Genetics Unit, OMMA, Ophthalmological Institute of Athens, Katehaki 74, 11525, Athens, Greece.
⁵ Great Ormond Street Hospital for Children, London, WC1N 3JH, UK.

Abstract

Purpose: To investigate the association between novel PAX6 mutations to bilateral anterior pyramidal congenital cataracts (APyC), complete and intact irides, and nystagmus.

Observations: This is a retrospective observational case series in a multi-center setting with genetic testing. Three female patients were diagnosed with bilateral APyC, intact irides and nystagmus. Genetic testing identified the three patients had novel missense mutations in PAX6 - c.128C > T; p.Ser43Phe (S43F), c. 197T > A; p.Ile66Asn (I66N) and c.781C > G; p.Arg261Gly (R261G).

Conclusions and importance: This study demonstrates a novel phenotype of bilateral APyC, intact irides, and nystagmus in whom genetic testing for PAX6 identified novel missense mutations (S43F, I66N, R261G) in highly conserved DNA-binding domains. Implications of understanding why the iris is present in these cases is discussed.

Keywords: Intact irides; Novel PAX6 missense mutations; Nystagmus; Pyramidal cataracts.