Subtelomeric study of 132 patients with mental retardation reveals 9 chromosomal anomalies and contributes to the delineation of submicroscopic deletions of 1pter, 2qter, 4pter, 5qter and 9qter

Abstract

Background: Cryptic chromosome imbalances are increasingly acknowledged as a cause for mental retardation and learning disability. New phenotypes associated with specific rearrangements are also being recognized. Techniques for screening for subtelomeric rearrangements are commercially available, allowing the implementation in a diagnostic service laboratory. We report the diagnostic yield in a series of 132 subjects with mental retardation, and the associated clinical phenotypes.

Chromosome 2q37 deletion: Clinical and molecular aspects

“…Nearly 100 individuals carrying isolated, primarily terminal deletions with breakpoint at or within chromosome 2 region q37 have been reported previously [Gorski et al, 1989;Lamb et al, 1990;Coldwell et al, 1992;Lin et al, 1992;Oley et al, 1992;Haag et al, 1993;Waters et al, 1993;Fisher et al, 1994;Stratton et al, 1994;Wang et al, 1994;Conrad et al, 1995;Phelan et al, 1995;Wilson et al, 1995;Rauch et al, 1996;Friedman et al, 1997;Power et al, 1997;Wenger et al, 1997;Viot-Szoboszlai et al, 1998;Ghaziuddin and Burmeister, 1999;Reddy et al, 1999;Lehman et al, 2001;Smith et al, 2001;Anderlid et al, 2002;Wolff et al, 2002;van Karnebeek et al, 2002;Giardino et al, 2003;Aldred et al, 2004;Casas et al, 2004;Chassaing et al, 2004;Lukusa et al, 2004;Polityko et al, 2004;Shrimpton et al, 2004;Adeyinka et al, 2005;Sogaard et al, 2005;Chaabouni et al, 2006;Lacbawan et al, 2006;Masumoto et al, 2006;Ravnan et al, 2006], though some of the reports have not included detailed clinical characterization. In addition Nearly 100 individuals carrying isolat...…”

“…Clinically significant microdeletions usually occur as de novo events, but exceptions have been noted. Sogaard et al [2005] reported a phenotypically normal mother with the 2q37.3 deletion polymorphism whose child had mental retardation and physical anomalies associated with a larger 6.8 Mb 2q37 microdeletion. van Karnebeek et al [2002] …”

Molecular characterization of a new patient with a non‐recurrent inv dup del 2q and review of the mechanisms for this rearrangement

“…A polymorphism at the 2q telomere was first identified by Macina et al [1994] and using multiple subtelomeric probes in a study of 150 patients, indicated that 6% of these patients had a 2qtel deletion and they concluded that the deletion of the locus D2S2986 in the 2qtel region was a common variant. Sogaard et al [2005] reported a phenotypically normal mother with a 2q37.3 deletion polymorphism whose child had clinical manifestations associated with a larger microdeletion (6.8 Mb). Similarly, Van Karnebeek et al [2002] described a microdeletion distal to 2q37.3 in a phenotypically normal father whose daughter showed clinical manifestations of a 2q37.3 terminal deletion.…”

The 2q37-deletion syndrome: an update of the clinical spectrum including overweight, brachydactyly and behavioural features in 14 new patients

“…A precise mapping of the deletions, however, was carried out in only a few studies (27/115 patients). [1][2][3][4][5][6][7][8][9][10]13,14,24,25,30,32 The patients with purely distal deletions (seven females, three males) included in the DECIPHER database (http://decipher.sanger.ac.uk/) had various deletion sizes ranging from 3 to 9.9 Mb. Unfortunately, clinical features were only mentioned for 2 of the 10 patients.…”