Introduction: Smith-Magenis syndrome (SMS) is rare (prevalence 1/25.000) and associates psychomotor delay, a particular behavioral pattern and congenital anomalies. SMS is often due to less than 4 Mb chromosomal deletion at 17p11.2 locus, leading to haploinsufficiency of numerous genes. Mutations of one of them, RAI1, seems to be responsible of main criteria foud in heterozygous 17p11.2 deletion.
Materials and Methods: We studied DNA from 30 SMS patients using a 300 bp-amplimers-CGH-array encompassing 75 loci on the 22 Mb from chromosome 17 short arm.
Results: Three patients showed larger deletions (10%). Genotype-phenotype correlation revealed that two of them had cleft palate beside none of other SMS patients (p<0,007, Fisher's exact test). The smallest cleft palate SMS extra-deleted region of 1,4 Mb contains less than 16 genes and is located at 17p11.2-17p12. Among them, gene expression array data showed that Ubiquitin B precursor (UBB) is significantly expressed in first branchial arch at 4th and 5th of human development.
Conclusion: Therefore, all these data may support UBB as a good candidate gene for isolated cleft palate.
- cleft palate