Alignment of the minimal region of duplication to the human genome reduced the minimal TND critical region, formerly estimated at 440 kb, to 160-173 kb, revealing PLAGL1 (pleiomorphic adenoma gene-like 1) and HYMAI (imprinted in hydatidiform mole) to be the only genes wholly included therein.
Two imprinted genes, ZAC (zinc finger protein associated with apoptosis and cell cycle arrest) and HYMAI (imprinted in hydatidiform mole) have been identified as potential candidates.