Supplementary Material for: Clinical and Molecular Cytogenetic Characterization of a de novo Interstitial 1p31.1p31.3 Deletion in a Boy with Moderate Intellectual Disability and Severe Language Impairment E.Tassano A.Gamucci M.E.Celle P.Ronchetto C.Cuoco G.Gimelli 2015 Interstitial 1p deletions are rare events. Very few cases of 1p31.1p31.3 deletions characterized by variable phenotypes have been reported. No clear genotype-phenotype correlation has been determined yet. We present a child with a de novo interstitial 1p31.1p31.3 deletion, identified by array CGH, associated with intellectual disability and severe language impairment. The deleted region contains 20 OMIM genes, but we focused on <i>GADD45A</i> (MIM 126335; growth arrest- and DNA damage-inducible gene), <i>LRRC7</i> (MIM 614453; leucine-rich repeat-containing protein 7), and <i>NEGR1</i> (MIM 613173; neuronal growth regulator 1). We discuss whether these genes play a role in determining the phenotype of our patient in order to investigate the possibility of a genotype-phenotype correlation.