title: Reciprocal translocations: a trap for cytogenetists?
abstract: We report four cases of subjects with phenotypic abnormalities and mental retardation associated with apparently balanced translocations, two inherited and two de novo, which showed, by molecular analysis, a hidden complexity. All the cases have been analyzed with different molecular techniques, including array-CGH, and in two of them the translocation breakpoints have been defined at the level of base pairs via studies in somatic hybrids containing single derivative chromosomes. We demonstrated that all the translocations were in fact complex rearrangements and that an imbalance was present in three of them, thus accounting for the phenotypic abnormalities. In one case, a Prader-Willi subject, we were not able to determine the molecular cause of his phenotype. This study, while confirming previous data showing unexpected complexity in translocations, further underscores the need for molecular investigations before taking for granted an apparently simple cytogenetic interpretation.
authors.affiliation: Biologia Generale e Genetica Medica, Università di Pavia, Pavia, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Ciccone
authors.forename: Roberto
authors.initials: R
authors.lastname: Giorda
authors.forename: Giuliana
authors.initials: G
authors.lastname: Gregato
authors.forename: Renzo
authors.initials: R
authors.lastname: Guerrini
authors.forename: Sabrina
authors.initials: S
authors.lastname: Giglio
authors.forename: Romeo
authors.initials: R
authors.lastname: Carrozzo
authors.forename: Maria Clara
authors.initials: MC
authors.lastname: Bonaglia
authors.forename: Emanuela
authors.initials: E
authors.lastname: Priolo
authors.forename: Carmelo
authors.initials: C
authors.lastname: Laganà
authors.forename: Romano
authors.initials: R
authors.lastname: Tenconi
authors.forename: Mariano
authors.initials: M
authors.lastname: Rocchi
authors.forename: Tiziano
authors.initials: T
authors.lastname: Pramparo
authors.forename: Orsetta
authors.initials: O
authors.lastname: Zuffardi
authors.forename: Elena
authors.initials: E
authors.lastname: Rossi
mesh_terms: D000015:Abnormalities, Multiple / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D002869:Chromosome Aberrations; D005260:Female; D015321:Gene Rearrangement; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics*; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D011218:Prader-Willi Syndrome / Q000235:genetics; D014178:Translocation, Genetic