Temple syndrome (TS) is an imprinting disorder of chromosome 14 that has a clinical phenotype similar to that of
Prader-Willi Syndrome (PWS). Individuals with TS can have short stature, intrauterine growth restriction (IUGR),
precocious puberty, truncal hypotonia, motor delay, scoliosis and feeding problems in infancy (Ioannides Y et al 2014).
Imprinting at chromosome 14 occurs at 14q32. Methylation of the intergenic differentially methylated control region
(IG-DMR) between DLK1 and GTL2/MEG3 on the paternal chromosome results in the expression of protein coding
DLK1, RTL1 and DIO3 genes and suppression of the maternal non-coding RNA genes of GTL2/MEG3, MEG8 and
RTL1as (Ioannides Y et al 2014).
In TS there is dysregulation of expression of genes at this locus. In the majority of cases (78.4%) this is due to
maternal UPD of chromosome 14, resulting in overexpression of the maternally expressed genes and loss of
expression of paternally expressed genes. Around 10% of cases of TS are due to a deletion of the paternal 14q32
locus and around 12% of cases are due to loss of methylation (LOM) at the MEG3/DLK1 IG-DMR and MEG3 TSS-DMR
(Soellner L et al 2017).