Italian Journal of Pediatrics (Feb 2010)

"Idiopathic" mental retardation and new chromosomal abnormalities

  • El-Malhany Nadia,
  • Lo-Castro Adriana,
  • Galasso Cinzia,
  • Curatolo Paolo

DOI
https://doi.org/10.1186/1824-7288-36-17
Journal volume & issue
Vol. 36, no. 1
p. 17

Abstract

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Abstract Mental retardation is a heterogeneous condition, affecting 1-3% of general population. In the last few years, several emerging clinical entities have been described, due to the advent of newest genetic techniques, such as array Comparative Genomic Hybridization. The detection of cryptic microdeletion/microduplication abnormalities has allowed genotype-phenotype correlations, delineating recognizable syndromic conditions that are herein reviewed. With the aim to provide to Paediatricians a combined clinical and genetic approach to the child with cognitive impairment, a practical diagnostic algorithm is also illustrated. The use of microarray platforms has further reduced the percentage of "idiopathic" forms of mental retardation, previously accounted for about half of total cases. We discussed the putative pathways at the basis of remaining "pure idiopathic" forms of mental retardation, highlighting possible environmental and epigenetic mechanisms as causes of altered cognition.