Table 1. Descriptive characteristics of the included studies.

Author	Year	Country of study	Case Number	Male	Deletion	mUPD	Age (y) M+SD (Range)	PWS diagnosis	Outcome
Sinnema et al. [24]	2011	Netherlands	97	NA	53	44	36.2+12.4 (18-66)	MLPA	Psychiatry
Mass et al. [25]	2010	Netherlands	79	34	45	33	34.4+11.8 (18-65)	DNA methylation studies on the SNURF/SNRPN locus	Psychiatry
Dykens et al. [11]	2008	USA	88	43	55	33	22.41+11.74 (5-51)	FISH, methylation studies, or MLPA/MS-MLPA	Psychiatry, IQ
Soni et al. [26]	2008	UK	46	21	24	22	31.2+9.6 (12-51)	microsatellite analysis	Psychiatry, IQ
Zarcone et al. [27]	2007	USA	73	20	42	31	22.7+9.4 (10-40)	FISH and DNA microsatellite analysis	IQ
Descheemaeker et al. [19]	2006	Belgium	59	31	40	18	21.2 (2-51)	chromosome examination and DNA methylation	IQ
Milner et al. [28]	2005	UK	96	51	47	49	16.3+12.4 (3.3-50)	quantitative fluorescent PCR assay, microsatellite analysis	IQ
Walley et al. [29]	2005	UK	18	11	12	6	23.5+7.8 (16-49)	molecular genetic testing, no detail	IQ
Bulter et al. [30]	2004	USA	46	21	25	21	23+8.6	FISH, methylation and microsatellite analysis	IQ
Boer et al. [31]	2002	UK	15	8	9	5	38.5+5.7 (29-47)	methylation pattern	Psychiatry, IQ
FOX et al. [32]	2001	USA	43	NA	24	19	23.3+8.7	FISH, methylation and microsatellite analysis	IQ
Roof et al. [21]	2000	USA	38	16	24	14	22.2+9.1 (10-44)	high-resolution chromosome analysis, DNA microsatellite analysis	IQ
Dykens et al. [33]	1999	USA	46	18	23	23	17+9.42 (6-42)	molecular genetic testing, no detail	IQ

Note: MLPA, multiplex ligation-dependent probe amplification; FISH, fluorescence in situ hybridization; NA: not available.