This gene encodes a member of the evolutionarily conserved NOL1/NOP2/Sun domain family. The encoded protein may function as a DNA methyltransferase in the nucleus. This gene is deleted in Williams syndrome, a multisystem developmental disorder caused by the deletion of contiguous genes at 7q11.23. Alternative splicing of this gene results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Dec 2009].