Cat eye syndrome caused by 22q11.1q11.21 duplication: case report in a Chinese family

PURPOSE: This paper presents a report on two uncommon instances of cat eye syndrome in a Chinese family. CASE PRESENTATION: The proband, a 23-year-old female, exhibited a diminutive cornea and complete blindness in her right eye, and the uncorrected distance visual acuity of her left eye was 0.7 LogMAR. Peripheral blood chromosome karyotyping reveal a karyotype of 47, XX, + mar. Subsequent analysis of chromosome copy number variation unveiled a 1.5 Mb duplication in the 22q11.1q11.21 region of the proband. The proband's mother,aged 49, displayed small eyes, wide-set eyes, downward slanting eyelids, and congenital heart disease. Chromosome copy number variation analysis also showed a 1.55 Mb duplication in the 22q11.1q11.21 region of chromosome 22 in the proband's mother. Ultimately, both members of this family were diagnosed with cat eye syndrome. CONCLUSION: Cat eye syndrome is a rare genetic disorder that greatly affects patients' lives and requires personalized treatment. This study provides new evidence for a better understanding of the diagnosis of cat eye syndrome and emphasizes the importance of genetic counseling and supervision.