Ocular manifestations of 22q11.2 microduplication

Abstract

Purpose: To report a new ocular manifestation of the dup22q11 syndrome and explore involved genes that may offer insight to mechanisms of pathogenesis.

Design: Case series.

Participants: Two male patients with this syndrome diagnosed with dup22q11.2.

Methods: Medical records were reviewed. Duplication was detected in the oligo-single nucleotide polymorphism chromosomal microarray and duplicated genes within the segment where determined by literature and database review. Potential associations between the ophthalmologic manifestations and their physiopathology were investigated.

Main outcome measures: Microarray results and identification of candidate genes within the duplicated segment.

Results: Our patients demonstrate previously unreported findings of dup22q11.2, including Marcus Gunn jaw winking, Duane's retraction syndrome, and other abnormal eye movements consistent with a congenital cranial dysinnervation disorder (CCDD), retinal vascular tortuosity, and primary infantile glaucoma. The duplicated segment in case 1 includes SNAP29, which could be linked with the development of retinal vascular tortuosity, and MAPK1, which seems to play a role in axonal development through the semaphorin pathway, which may serve as a candidate gene for CCDD. In case 2, the CLDN5 gene is within the duplicated segment. CLDN5 could be involved in the pathophysiology of glaucoma.

Conclusions: Our cases expand the ocular phenotype for duplication of 22q11 and serve to identify potential candidate genes for the development of CCDD, retinal vascular tortuosity, and glaucoma.