Twenty-three patients (12.8%), but none of the controls, showed structural variants (deletions and insertions) in either of two markers related with lissencephaly (D17S1566 on tumor suppressor gene TP53: tumor protein p53 and D17S22 on SMG6 gene: Smg-6 homolog, nonsense mediated mRNA decay factor- Caenorhabditis elegans).