title: Partial tetrasomy of chromosome 22q11.1 resulting from a supernumerary isodicentric marker chromosome in a boy with cat-eye syndrome.
abstract: The 22q11 region has been implicated in chromosomal rearrangements that result in altered gene dosage, leading to three different congenital malformation syndromes: DiGeorge syndrome, cat-eye syndrome (CES), and der(22) syndrome. Although DiGeorge syndrome is a common genomic disorder on 22q11, CES is quite rare, and there has been no report of Korean CES cases with molecular cytogenetic confirmation. In this study, we present the phenotypic and genetic characteristics of a 3-month-old boy with CES. Clinical findings included micropthalmia, multiple colobomata, and renal and genital anomalies. Cytogenetic analyses showed the presence of a supernumerary marker chromosome, which was identified as a bisatellited and isodicentric chromosome derived from an acrocentric chromosome. The results of array comparative genomic hybridization and fluorescence in situ hybridization studies confirmed the karyotype as 47,XY,+mar.ish idic(22)(q11.1) (D22S43+).arr 22q11.1(15,500,000-15,900,000)x4, resulting in a partial tetrasomy of 22q11.1. To the best of our knowledge, this is the first report in Korea of CES confirmed by cytogenetic and molecular cytogenetic analyses.
authors.affiliation: Department of Medical Genetics, Ajou Medical Center, Ajou University School of Medicine, Suwon, Korea. jmko@ajou.ac.kr
authors.forename: Jung Min
authors.initials: JM
authors.lastname: Ko
authors.forename: Jun Bum
authors.initials: JB
authors.lastname: Kim
authors.forename: Ki Soo
authors.initials: KS
authors.lastname: Pai
authors.forename: Jun-No
authors.initials: JN
authors.lastname: Yun
authors.forename: Sang-Jin
authors.initials: SJ
authors.lastname: Park
mesh_terms: D000015:Abnormalities, Multiple / Q000235:genetics; D000782:Aneuploidy; D025063:Chromosome Disorders / Q000175:diagnosis / Q000235:genetics; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics; D003103:Coloboma / Q000235:genetics; D019465:Craniofacial Abnormalities / Q000235:genetics; D005124:Eye Abnormalities; D005819:Genetic Markers; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D007621:Karyotyping; D008297:Male; D010641:Phenotype; D058670:Tetrasomy; D016216:Ultrasonography, Prenatal
chemical_list: D005819:Genetic Markers