2q23.1 microdeletion identified by array comparative genomic hybridisation: an emerging phenotype with Angelman-like features?
- S Jaillard1,2,
- C Dubourg2,3,
- M Gérard-Blanluet4,
- A Delahaye5,
- L Pasquier2,6,
- C Dupont4,5,
- C Henry1,
- A-C Tabet4,
- J Lucas1,
- A Aboura4,
- V David2,3,
- B Benzacken4,5,
- S Odent2,6,
- E Pipiras5
- 1Histology Cytogenetic Department, Pontchaillou University Hospital, Rennes, France
- 2UMR 6061, IFR 140 GFAS, Faculty of Medecine, Rennes, France
- 3Molecular Genetics Department, Pontchaillou University Hospital, Rennes, France
- 4Genetics Department, INSERM U676, AP-HP, Robert Debré University Hospital, Paris, France
- 5Histology Embryology Cytogenetics Department, Jean Verdier University Hospital, Bondy, AP-HP, UFR-USMBH, Paris, France
- 6Genetics Department, Hôpital Sud University Hospital, Rennes, France
- Correspondence to Dr S Jaillard, Histology Cytogenetic Department, Pontchaillou University Hospital, Zrue Henri Le Guilloux, 35033 Rennes Cedex, France; sylvie.jaillard{at}chu-rennes.fr
- Received 14 February 2008
- Revised 19 May 2008
- Accepted 21 May 2008
- Published Online First 23 September 2008
Abstract
Background: Genome-wide screening of patients with mental retardation using array comparative genomic hybridisation (CGH) has identified several novel imbalances. With this genotype-first approach, the 2q22.3q23.3 deletion was recently described as a novel microdeletion syndrome. The authors report two unrelated patients with a de novo interstitial deletion mapping in this genomic region and presenting similar “pseudo-Angelman” phenotypes, including severe psychomotor retardation, speech impairment, epilepsy, microcephaly, ataxia, and behavioural disabilities.
Methods: The microdeletions were identified by array CGH using oligonucleotide and bacterial artificial chromosome (BAC) arrays, and further confirmed by fluorescence in situ hybridisation (FISH) and semi-quantitative polymerase chain reaction (PCR).
Results: The boundaries and sizes of the deletions in the two patients were different but an overlapping region of about 250 kb was defined, which mapped to 2q23.1 and included two genes: MBD5 and EPC2. The SIP1 gene associated with the Mowat–Wilson syndrome was not included in the deleted genomic region.
Discussion: Haploinsufficiency of one of the deleted genes (MBD5 or EPC2) could be responsible for the common clinical features observed in the 2q23.1 microdeletion syndrome, and this hypothesis needs further investigation.
Footnotes
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Funding This research was supported by grants from the Centre Hospitalier et Universitaire de Rennes (concours post-internat), PHRC inter-régional du Grand Ouest, and from the Centre Hospitalier et Universitaire Jean Verdier, Paris.
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Competing interests None declared.
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Patient consent Obtained.
