Predominantly expressed in testis and heart. SPDYE1 is located in the Williams-Beuren syndrome (WBS) critical region. WBS results from a hemizygous deletion of several genes on chromosome 7q11.23, thought to arise as a consequence of unequal crossing over between highly homologous low-copy repeat sequences flanking the deleted region (PubMed:12073013). Belongs to the Speedy/Ringo family.