Mosaic cat eye syndrome in a child with unilateral iris coloboma

• Published in: Ophthalmic genetics 2021-02, Vol.42 (1), p.84-87
• Main Authors: Hernández-Medrano, Cristina, Hidalgo-Bravo, Alberto, Villanueva-Mendoza, Cristina, Bautista-Tirado, Teresa, Apam-Garduño, David
• Format: Article
• Language: English
• ISSN: 1381-6810; 1744-5094
• DOI: 10.1080/13816810.2020.1839918

Cat eye syndrome (CES) is a rare chromosomal disorder with a known incidence of 1 per 50,000-150,000 live newborns. The classic triad of iris coloboma, anorectal malformations, and auricular abnormalities is present in 40% of patients. In addition, other ocular malformations and systemic defects can be present. The aim of this report is to present a patient with unilateral iris coloboma related to a mosaicism of cat eye syndrome. A complete ophthalmological and systemic evaluation was performed in a three-year-old male. He also underwent a standard karyotype and FISH analysis with a probe against the 22q11.2 locus. The ophthalmological and systemic evaluation revealed a unilateral iris coloboma and ipsilateral auricular malformations. Karyotype analysis of blood leukocytes indicated the presence of a marker chromosome in 6% of the analyzed cells. FISH analysis showed three positive signals in 5.5% of the analyzed nucleus. This patient presented two of the three classic manifestations of CES; interestingly, they were unilateral. The 22q11 duplication was identified by standard karyotype and confirmed with FISH. The present case demonstrates the importance of conducting a multidisciplinary approach in patients with congenital malformations associated with known syndromes.