title: Partial monosomy 21 (q11.2→q21.3) combined with 3p25.3→pter monosomy due to an unbalanced translocation in a patient presenting dysmorphic features and developmental delay.
abstract: We describe a female patient of 1 year and 5 months-old, referred for genetic evaluation due to neuropsychomotor delay, hearing impairment and dysmorphic features. The patient presents a partial chromosome 21 monosomy (q11.2→q21.3) in combination with a chromosome 3p terminal monosomy (p25.3→pter) due to an unbalanced de novo translocation. The translocation was confirmed by fluorescence in situ hybridization (FISH) and the breakpoints were mapped with high resolution array. After the combined analyses with these techniques the final karyotype was defined as 45,XX,der(3)t(3;21)(p25.3;q21.3)dn,-21.ish der(3)t(3;21)(RP11-329A2-,RP11-439F4-,RP11-95E11-,CTB-63H24+).arr 3p26.3p25.3(35,333-10,888,738))×1,21q11.2q21.3(13,354,643-27,357,765)×1. Analysis of microsatellite DNA markers pointed to a paternal origin for the chromosome rearrangement. This is the first case described with a partial proximal monosomy 21 combined with a 3p terminal monosomy due to a de novo unbalanced translocation.
authors.affiliation: Department of Medical Genetics, Faculty of Medical Sciences, University of Campinas, UNICAMP, Campinas, SP, Brazil.
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: dos Santos
authors.forename: Társis Paiva
authors.initials: TP
authors.lastname: Vieira
authors.forename: Milena
authors.initials: M
authors.lastname: Simioni
authors.forename: Fabíola Paoli
authors.initials: FP
authors.lastname: Monteiro
authors.forename: Vera Lúcia
authors.initials: VL
authors.lastname: Gil-da-Silva-Lopes
mesh_terms: D002872:Chromosome Deletion; D002891:Chromosomes, Human, Pair 21; D002893:Chromosomes, Human, Pair 3; D002658:Developmental Disabilities / Q000209:etiology / Q000235:genetics*; D005145:Face / Q000002:abnormalities; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D007621:Karyotyping; D018895:Microsatellite Repeats; D009006:Monosomy; D014178:Translocation, Genetic