title: Duplication of chromosome region 4q28.3-qter in monozygotic twins with discordant phenotypes.
abstract: We describe monozygotic twins with partially discordant phenotypes who were found to have a duplication of chromosome region 4q28.3-qter. The duplicated region of chromosome 4 resulted from an unbalanced segregation of a balanced maternal (4;22)(q28.3;p13) translocation. Duplication of the long arm of chromosome 4 has been described in >60 patients; however, it usually results from the unbalanced segregation of a parental balanced translocation and has an associated monosomy. Twenty cases of dup 4q without an associated monosomy have been reported, and this is the only case of dup 4q28. 3-qter. All cases of dup 4q are reviewed, and phenotypic aspects are analyzed. Issues of monozygotic twinning and other birth defects also are addressed.
authors.affiliation: The Division of Human Genetics and Molecular Biology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA.
authors.forename: L
authors.initials: L
authors.lastname: Celle
authors.forename: L
authors.initials: L
authors.lastname: Lee
authors.forename: N
authors.initials: N
authors.lastname: Rintoul
authors.forename: R C
authors.initials: RC
authors.lastname: Savani
authors.forename: W
authors.initials: W
authors.lastname: Long
authors.forename: M T
authors.initials: MT
authors.lastname: Mennuti
authors.forename: I D
authors.initials: ID
authors.lastname: Krantz
mesh_terms: D002869:Chromosome Aberrations; D002874:Chromosome Mapping; D002894:Chromosomes, Human, Pair 4; D020440:Gene Duplication; D006801:Humans; D007223:Infant; D007621:Karyotyping; D008297:Male; D010641:Phenotype; D018433:Twin Studies as Topic; D014430:Twins, Monozygotic / Q000235:genetics*