In human neonatal foreskin DIO3 (deiodinase, iodothyronine, type III) showed biased allelic
expression with an average imbalance of 74:36. In two cases the more highly expressed allele was
paternally derived. However, in one adult skin sample the materally derived allele was more highly
expressed. It was suggested that the different parent-of-origin is attributable to different
promoter usage (Martinez ME et al, 2016).
In placenta, protein expression and quantitative real-time PCR showed that DIO3 expression was
similar between three patients with paternal UPD14 and controls,
arguing against imprinting
(Kagami M et al, 2012).
Ogata T & Kagami M (2015) argue that absence of
hypothyroidism in Kagami-Ogata syndrome and hyperthyroidism in Temple syndrome (imprinting disorders) indicates
that DIO3 isnít an imprinted gene, as DIO3 acts as an inactivator of thyroid hormones.
The mouse homologue of DIO3 is imprinted (Hernandez A et al, 2002).
Comment: More data are needed (both number of informative samples, and evidence of different