Loss of methylation: A patient with clinical features of maternal UPD14,
including growth retardation, hypotonia, scoliosis, small hands
and feet, and advanced puberty, had loss of methylation
of the the MEG3 promoter CpG island (which they refer to as the IG-DMR) but no evidence of maternal
IK et al, 2007). This case
provided support for the hypothesis that the maternal UPD14
phenotype is due to aberrant gene expression within the
imprinted domain at 14q32.
Gain of methylation: Three cases with methylation of the normally unmethylated maternal allele of
IG-DMR showed a paternal-UPD(14)-like phenotype (Kagami
M et al, 2008).