Exploring the unique function of imprinting control centers in the PWS/AS-responsible region: finding from array-based methylation analysis in cases with variously sized microdeletions

Table 1 Clinical information, deletion range, and methylation status at SNRPN-DMR in cases enrolled in this study

Cases		Phenotype	Sex	Age^a	Breakpoint (approximate size)	Methylation status at SNRPN-DMR^d
Case 1		PWS	Male	2 mo	Chr15:25,150,978-25,225,535 (75 kb)^b	Hypermethylated
Case 2		Healthy carrier (father of case 1)	Male	36 yr	Chr15:25,150,978-25,225,535 (75 kb)^b	Hypomethylated
Case 3		PWS	Female	3 yr	Chr15:25,216,569-25,415,670 (200 kb)^b	Normal
Case 4		AS	Female	3 yr	Chr15:25,126,774-25,168,037 (41 kb)^b	Hypomethylated
Case 5		AS	Male	4 yr	Chr15:25,164,853-25,168,575 (3.7 kb)^b	Hypomethylated
Case 6		Healthy carrier (mother of case 5)	Female	36 yr	Chr15:25,164,853-25,168,575 (3.7 kb)^b	Normal
PWS_LD	PWS_LD-1	PWS	Male	0 mo	BP2–3 (5.5 Mb)^c	Hypermethylated
	PWS_LD-2	PWS	Male	2 mo	BP1–3 (6 Mb)^c	Hypermethylated
	PWS_LD-3	PWS	Male	3 yr	BP1–3 (6 Mb)^c	Hypermethylated
	PWS_LD-4	PWS	Male	8 yr	BP1–3 (6 Mb)^c	Hypermethylated
AS_LD	AS_LD-1	AS	Female	9 yr	BP2–3 (5.5 Mb)^c	Hypomethylated
	AS_LD-2	AS	Female	9 yr	BP2–3 (5.5 Mb)^c	Hypomethylated
	AS_LD-3	AS	Male	2 yr	BP1–3 (6 Mb)^c	Hypomethylated
	AS_LD-4	AS	Female	1 yr	BP1–3 (6 Mb)^c	Hypomethylated

PWS Prader-Willi syndrome, AS Angelman syndrome, DMR differentially methylated region, LD large deletion, BP breakpoint
^aAge at sample collection (mo months, yr years)
^bThe breakpoints were estimated according to the results of aCGH
^cThe breakpoints were estimated according to the results of methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA). The locations of BPs are shown in Additional file 2: Figure S1
^dMethylation status were examined by MS-MLPA

ISSN: 1868-7083