Genotype–phenotype correlation of 30 patients with Smith-Magenis syndrome (SMS) using comparative genome hybridisation array: cleft palate in SMS is associated with larger deletions
- J Andrieux1,2,
- C Villenet2,
- S Quief2,
- S Lignon2,
- S Geffroy2,
- C Roumier2,
- H de Leersnyder3,
- M-C de Blois3,
- S Manouvrier4,
- B Delobel5,
- B Benzacken6,
- P Bitoun7,
- T Attie-Bitach3,
- S Thomas3,
- S Lyonnet3,
- M Vekemans3,
- J-P Kerckaert2
- 1Laboratoires de Génétique Médicale, Hôpital Jeanne de Flandre, Lille, France
- 2Plateforme de Génomique Fonctionnelle, Université de Lille II, Lille, France
- 3Département de Génétique et INSERM U-393, Hôpital Necker-Enfants Malades, Paris, France
- 4Service de Génétique Clinique, Hôpital Jeanne de Flandre, Lille, France
- 5Centre de Génétique Chromosomique, Université Catholique, Lille, France
- 6Laboratoire de cytogénétique et Biologie de la Reproduction, Hôpital Jean Verdier, AP-HP, Bondy, France
- 7Génétique Médicale, Hôpital Jean Verdier, AP-HP, Bondy, France
- Correspondence to: J Andrieux Laboratoires de Génétique Médicale, Hôpital Jeanne de Flandre, Lille 59000, France; j-andrieux{at}chru-lille.fr
- Received 22 December 2006
- Accepted 4 April 2007
- Revised 1 April 2007
- Published Online First 27 April 2007
Abstract
Background: Smith-Magenis syndrome (SMS) is rare (prevalence 1 in 25 000) and is associated with psychomotor delay, a particular behavioural pattern and congenital anomalies. SMS is often due to a chromosomal deletion of <4 Mb at the 17p11.2 locus, leading to haploinsufficiency of numerous genes. Mutations of one of these gemes, RAI1, seems to be responsible for the main features found with heterozygous 17p11.2 deletions.
Methods: We studied DNA from 30 patients with SMS using a 300 bp amplimers comparative genome hybridisation array encompassing 75 loci from a 22 Mb section from the short arm of chromosome 17.
Results: Three patients had large deletions (10%). Genotype–phenotype correlation showed that two of them had cleft palate, which was not found in any of the other patients with SMS (p<0.007, Fisher’s exact test). The smallest extra-deleted region associated with cleft palate in SMS is 1.4 Mb, contains <16 genes and is located at 17p11.2-17p12. Gene expression array data showed that the ubiquitin B precursor (UBB) is significantly expressed in the first branchial arch in the fourth and fifth weeks of human development.
Conclusion: These data support UBB as a good candidate gene for isolated cleft palate.
- CGH, comparative genome hybridisation
- FISH, fluorescence hybridisation
- HMM, hidden Markov model
- UBB, ubiquitin B
Footnotes
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Competing interests: None declared.
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Published Online First 11 May 2007







