A CpG island (CpG#59) 8 kb downstream of exon 1 of DSCR3 (Down syndrome critical region protein 3)
was maternally methylated in a subset of peripheral blood leukocytes and in some placentas.
Differential methylation was detected by PCR following DNA digestion with either HpaII or McrBC
(methylation sensitive and dependent restriction enzymes respectively) (Yamada
Y et al, 2004).