IGFBP2 and Down syndrome: CYFIP1 is localized in the BP1-BP2 region of human chromosome 15q11.2 (Abekhoukh and Bardoni, 2014) and deletion of this region (including the NIPA1, NIPA2, TUBGCP5 and WHAM genes) leads to the Burnside-Butler (BP1-BP2 microdeletion) syndrome, characterized by developmental and language delay, neurobehavioral disturbances and psychiatric problems, autism, seizures, schizophrenia and mild dysmorphic features (Cox and Butler, 2015).