YWHAE and Global developmental delay: Bruno et al.[5] proposed to divide 17p13.3 microduplications in two different classes: class I microduplications involving YWHAE but not PAFAH1B1 showing a phenotype characterized by learning difficulties and/or autism with or without other congenital abnormalities; class II microduplications always harboring PAFAH1B1 that may also include the genomic region encompassing the CRK and YWHAE genes, which are associated with developmental delay, psychomotor delay, and associated hypotonia.