ZFAT-AS1 showed monoallelic expression in at least 10 placentas investigated, and in three cases
the expressed allele could be determined and was paternal. However, biallelic expression was
observed in thyroid tumours (Barbaux S et al, 2012).
Metsula T et al (2014) reported
monoallelic paternal expression in 3/3 informative families. However, they also reported random
monoallelic expression of ZFAT itself.
Since it seems unlikely that ZFAT is imprinted then the imprinted expression of ZFAT-AS1 also seems
unlikely despite the reported 6/6 cases showing paternal expression.