title: An accessory marker derived from chromosome 20 and its co-existence with a mosaic trisomy 20 cell line.
abstract: We report a 16-month-old boy with delayed psychomotor development, dysmorphic features, and failure to thrive. He had a mosaic karyotype detected prenatally: mos 46,XY/47,XY, +r(20)/47,XY, +20. After birth, the abnormal cell lines were confirmed in a number of tissues. The small ring chromosome was identified using fluorescence in situ hybridization as derived from chromosome 20. We compared our patient with previously reported cases of mosaic trisomy 20 detected prenatally and associated with an abnormal phenotype. In an attempt to characterize an r(20) syndrome, we also compared our case with two similar reports in the literature.
authors.affiliation: Department of Gynecology and Obstetrics, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Batista
authors.forename: C
authors.initials: C
authors.lastname: Escallon
authors.forename: K J
authors.initials: KJ
authors.lastname: Blakemore
authors.forename: G
authors.initials: G
authors.lastname: Stetten
mesh_terms: D002460:Cell Line; D002890:Chromosomes, Human, Pair 20; D005500:Follow-Up Studies; D005819:Genetic Markers; D006801:Humans; D007223:Infant; D007621:Karyotyping; D008297:Male; D009030:Mosaicism; D010641:Phenotype; D011296:Prenatal Diagnosis; D012303:Ring Chromosomes; D014314:Trisomy
chemical_list: D005819:Genetic Markers