Research
Subtelomeric FISH analysis in 76 patients with syndromic developmental delay/intellectual disability
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* Corresponding author: Margherita C Silengo margherita.cirillosilengo@unito.it
- † Equal contributors
1 Dipartimento di Scienze Pediatriche, University of Torino, Torino, Italy
2 Dipartimento di Biologia Generale e Genetica Medica, University of Pavia, Pavia, Italy
3 S.C. Genetica Umana, E.O.Ospedali Galliera, Genova, Italy
Italian Journal of Pediatrics 2009, 35:9 doi:10.1186/1824-7288-35-9
Published: 27 April 2009Abstract
Background
Intellectual disability affects approximately 1 to 3% of the general population. The etiology is still poorly understood and it is estimated that one-half of the cases are due to genetic factors. Cryptic subtelomeric aberrations have been found in roughly 5 to 7% of all cases.
Methods
We performed a subtelomeric FISH analysis on 76 unrelated children with normal standard karyotype ascertained by developmental delay or intellectual disability, associated with congenital malformations, and/or facial dysmorphisms.
Results
Ten cryptic chromosomal anomalies have been identified in the whole cohort (13,16%), 8 in the group of patients characterized by developmental delay or intellectual disability associated with congenital malformations and facial dysmorphisms, 2 in patients with developmental delay or intellectual disability and facial dysmorphisms only.
Conclusion
We demonstrate that a careful clinical examination is a very useful tool for pre-selection of patients for genomic analysis, clearly enhancing the chromosomal anomaly detection rate. Clinical features of most of these patients are consistent with the corresponding emerging chromosome phenotypes, pointing out these new clinical syndromes associated with specific genomic imbalances.