OPHN1 and Cerebellar hypoplasia: The NGS test did not reveal any known SGF related genetic variant, although the test did indicate that the patient carries a missense mutation in the gene encoding SET binding protein 1 (SETBP1) (c.2608G>A [p.Gly870Ser]), a causative variation for Schinzel-Giedion syndrome (OMIM #269150) [44], a frameshift or nonsense mutation in SETBP1 known to cause autosomal dominant mental retardation-29 (OMIM #616078) [45], and a mutation in the oligophrenin-1 gene (OPHN1) known to cause X-linked mental retardation with cerebellar hypoplasia (OMIM #300486) [46].