title: Complex balanced translocation t(1;5;7)(p32.1;q14.3;p21.3) and two microdeletions del(1)(p31.1p31.1) and del(7)(p14.1p14.1) in a patient with features of Greig cephalopolysyndactyly and mental retardation.
abstract: Complex chromosome rearrangements (CCRs) are rare structural abnormalities that involve at least two chromosomes and more than two breakpoints and are often associated with developmental delay, mental retardation, and congenital anomalies. We report on a de novo, apparently balanced translocation t(1;5;7)(p32.1;q14.3;p21.3) involving three chromosomes in a 7-year-old boy with severe psychomotor retardation, neonatal muscular hypertonia, congenital heart defect, polysyndactyly of hands and feet, and dysmorphic features resembling Greig cephalopolysyndactyly syndrome. Analysis of the chromosome breakpoints using fluorescence in situ hybridization (FISH) with locus-specific BAC clones and long-range PCR products did not identify chromosome imbalance at any of the interrogated regions. High-resolution comparative genomic hybridization (HR-CGH) and array CGH (aCGH) revealed two additional cryptic de novo deletions, del(1)(p31.1p31.1) and del(7)(p14.1p14.1), respectively, that are not associated with the translocation breakpoints. FISH and polymorphic marker analyses showed that the deletion on derivative chromosome 1 is between 4.2 and 6.1 Mb, and the deletion on derivative chromosome 7 is approximately 5.1 Mb, and that both are paternal in origin. The deletion on chromosome 7p encompasses the GLI3 gene that is causative for the Greig cephalopolysyndactyly, Pallister-Hall and some cases of Acrocallosal syndromes. We discuss the potential mechanisms of formation of the described CCR.
authors.affiliation: Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Borg
authors.forename: Beata
authors.initials: B
authors.lastname: Nowakowska
authors.forename: Ewa
authors.initials: E
authors.lastname: Obersztyn
authors.forename: Sau Wai
authors.initials: SW
authors.lastname: Cheung
authors.forename: Joanna
authors.initials: J
authors.lastname: Brycz-Witkowska
authors.forename: Lech
authors.initials: L
authors.lastname: Korniszewski
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Mazurczak
authors.forename: Paweł
authors.initials: P
authors.lastname: Stankiewicz
authors.forename: Ewa
authors.initials: E
authors.lastname: Bocian
mesh_terms: D002648:Child; D002872:Chromosome Deletion; D002878:Chromosomes, Human, Pair 1; D002895:Chromosomes, Human, Pair 5; D002897:Chromosomes, Human, Pair 7; D020732:Cytogenetic Analysis; D006801:Humans; D008297:Male; D013576:Syndactyly / Q000235:genetics*; D013577:Syndrome; D014178:Translocation, Genetic