As several studies have shown evidence of disturbed gene expression patterns and behavioral findings in subjects with either PWS or Angelman syndrome with different genetic deletion subtypes implicating genes within the BP1 and BP2 genomic region, Burnside et al. [13] summarized the literature and surveyed the first large cohort of patients presenting for genetic testing using high resolution microarrays. This evidence concerns the gene IGFBP2 and Prader-Willi syndrome.