Based on observations of hypomethylation at ICR1 in SRS patients and the proposed role of CTCFL in directing DNA methylation at the Igf2/H19 ICR, we hypothesized that SRS patients with hypomethylation at ICR1 could potentially harbor mutations in CTCFL, which would provide a genetic link to the epimutations observed in these patients. Here, IGF2 is linked to Silver-Russell syndrome.