Table 1 11p15 abnormalities associated with overgrowth or growth retardation

	Copy number	Methylation profile		Phenotypes
	Copy number	H19 DMR	KvDMR1	Phenotypes
Overgrowth
Paternal duplication 11p15	Abnormal	Apparent HM*	Apparent LOM*	BWS-like
Maternal H19 DMR microdeletion	Abnormal	HM	Normal	BWS
Maternal KvDMR1 microdeletion	Abnormal	Normal	Apparent LOM*	BWS
Paternal UPD 11p15	Normal	HM	LOM	BWS, IHH
Hypermethylation H19 DMR	Normal	HM	Normal	BWS, IHH
Loss of methylation KvDMR1	Normal	Normal	LOM	BWS, IHH
CDKN1C mutation	Normal	Normal	Normal	BWS
Growth retardation
Maternal duplication 11p15	Abnormal	Apparent LOM*	Apparent HM*	SRS-like
Loss of methylation H19 DMR	Normal	LOM	Normal	SRS

HM, hypermethylation; LOM, loss of methylation; BWS, Beckwith–Wiedemann syndrome; SRS, Silver–Russell syndrome; UPD, uniparental disomy; IHH, isolated hemihypertrophy.
*Abnormal copy number at imprinting centres and the associated alteration in relative parental contribution results in apparent disturbances in methylation when assayed by most techniques.