Patient 2 and 3 with 0.25 Mb (chr20: 121521–373182) deletion of the 20p13, at this segmental deletion contain 10 Refseq genes, not found OMIM gene associated with phenotype, of which two candidate gene (SOX12 and NRSN2) was identified as nervous system expressing genes that may be associated with developmental delay [24]. The gene discussed is NRSN2; the disease is Global developmental delay.