title: Functional disomy of the Xq28 chromosome region.
abstract: We report on two patients, a boy and a girl, with an additional Xq28 chromosome segment translocated onto the long arm of an autosome. The karyotypes were 46,XY,der(10)t(X;10)(q28;qter) and 46,XX,der(4)t(X;4)(q28;q34), respectively. In both cases, the de novo cryptic unbalanced X-autosome translocation resulted in a Xq28 chromosome functional disomy. To our knowledge, at least 17 patients with a distal Xq chromosome functional disomy have been described in the literature. This is the third report of a girl with an unbalanced translocation yielding such a disomy. When the clinical features of both patients are compared to those observed in patients reported in the literature, a distinct phenotype emerges including severe mental retardation, facial dysmorphic features with a wide face, a small mouth and a thin pointed nose, major axial hypotonia, severe feeding problems and proneness to infections. A clinically oriented FISH study using subtelomeric probes is necessary to detect such a cryptic rearrangement.
authors.affiliation: Département de Génétique, Hôpital Necker-Enfants Malades, Paris, France. damien.sanlaville@nck.ap-hop-paris.fr
authors.forename: Damien
authors.initials: D
authors.lastname: Sanlaville
authors.forename: Marguerite
authors.initials: M
authors.lastname: Prieur
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: de Blois
authors.forename: David
authors.initials: D
authors.lastname: Genevieve
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Lapierre
authors.forename: Catherine
authors.initials: C
authors.lastname: Ozilou
authors.forename: Monique
authors.initials: M
authors.lastname: Picq
authors.forename: Philippe
authors.initials: P
authors.lastname: Gosset
authors.forename: Nicole
authors.initials: N
authors.lastname: Morichon-Delvallez
authors.forename: Arnold
authors.initials: A
authors.lastname: Munnich
authors.forename: Valerie
authors.initials: V
authors.lastname: Cormier-Daire
authors.forename: Genevieve
authors.initials: G
authors.lastname: Baujat
authors.forename: Serge
authors.initials: S
authors.lastname: Romana
authors.forename: Michel
authors.initials: M
authors.lastname: Vekemans
authors.forename: Catherine
authors.initials: C
authors.lastname: Turleau
mesh_terms: D000015:Abnormalities, Multiple / Q000235:genetics*; D000782:Aneuploidy; D002879:Chromosomes, Human, Pair 10 / Q000235:genetics*; D002894:Chromosomes, Human, Pair 4 / Q000235:genetics*; D041321:Chromosomes, Human, X / Q000235:genetics*; D005260:Female; D006801:Humans; D007223:Infant; D007621:Karyotyping; D008297:Male; D014178:Translocation, Genetic