This gene is located within a D4Z4 repeat array in the subtelomeric region of chromosome 4q. The D4Z4 repeat is polymorphic in length; a similar D4Z4 repeat array has been identified on chromosome 10. Each D4Z4 repeat unit has an open reading frame (named DUX4) that contains two homeoboxes; the repeat-array and ORF is conserved in other mammals. There was no evidence for transcription from standard cDNA libraries however RTPCR and in-vitro expression experiments indicate that the ORF is transcribed.
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