title: Ring chromosome 10: report on two patients and review of the literature.
abstract: Ring chromosome 10--r(10)--is a rare disorder, with 14 cases reported in the literature, but only two with breakpoint determination by high-resolution techniques. We report here on two patients presenting a ring chromosome 10, studied by G-banding, fluorescent in situ hybridization (FISH), multiplex ligation-dependent probe amplification (MLPA) and SNP-array techniques, in order to investigate ring instability and determine breakpoints. Patient 1 showed a r(10)(p15.3q26.2) with a 7.9 Mb deletion in 10q26.2-q26.2, while patient 2 showed a r(10)(p15.3q26.13) with a 1.0 Mb deletion in 10p15.3 and a 8.8 Mb deletion in 10q26.13-q26.3, both unstable. While patient 1 presented with clinical features usually found in patients with r(10) and terminal 10q deletion, patient 2 presented characteristics so far not described in other patients with r(10), such as Dandy-Walker variant, osteopenia, semi-flexed legs, and dermal pigmentation regions. Our data and the data from literature show that there are no specific clinical findings to define a r(10) syndrome.
authors.affiliation: Genetics Division, Department of Morphology and Genetics, Universidade Federal de São Paulo, Rua Botucatu 740, CEP 04023-900, São Paulo, Brazil.
authors.forename: Roberta Santos
authors.initials: RS
authors.lastname: Guilherme
authors.forename: Chong Ae
authors.initials: CA
authors.lastname: Kim
authors.forename: Luis Garcia
authors.initials: LG
authors.lastname: Alonso
authors.forename: Rachel S
authors.initials: RS
authors.lastname: Honjo
authors.forename: Vera Ayres
authors.initials: VA
authors.lastname: Meloni
authors.forename: Denise Maria
authors.initials: DM
authors.lastname: Christofolini
authors.forename: Leslie Domenici
authors.initials: LD
authors.lastname: Kulikowski
authors.forename: Maria Isabel
authors.initials: MI
authors.lastname: Melaragno
mesh_terms: D002871:Chromosome Banding; D002872:Chromosome Deletion; D002879:Chromosomes, Human, Pair 10 / Q000235:genetics*; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D060885:Multiplex Polymerase Chain Reaction; D012303:Ring Chromosomes