Table 1.

Ascertainment and study design of included studies

Authors	Included karyotypes	Prenatal diagnosed (%)	Study design
Ross et al, 2008	XXY	60	Cross‐sectional, comparison with normed reference group
Ross et al, 2009	XXY	55	Cross‐sectional, comparison with age‐matched controls
	XYY	29
Cordeiro et al, 2012	XXY	56	Cross‐sectional, comparison with normed reference group
	XYY	33
Bruining et al, 2009	XXY	51	Cross‐sectional, comparison with normed reference group
Ratcliffe, 2009	XXY	100	Cross‐sectional, comparison with controls and siblings
	XYY	95	Cross‐sectional, comparison with social class matched controls
	XXX	100	Cross‐sectional, comparison with female controls and siblings
Rovet et al, 1995; 1996	XXY	100	Cytogenetic survey followed by longitudinal follow‐up comparison with sibling controls
Netley, 1986	XXY	N/Aa	Summary of several cytogenetic surveys with longitudinal follow‐up, comparison group differed between groups, including family member, unrelated controls, or a normed reference group
	XXX
	XYY
Zampini et al, 2018	XXX/XXY	100	Cross‐sectional, comparison with controls
Haka‐Ikse et al, 1978	XXY	100	Cytogenetic survey followed by longitudinal follow‐up comparison with normed reference group
Bishop et al, 2011	XXX	51	Cross‐sectional, comparison with sibling controls
	XXY	100
	XYY	36
Lee et al, 2015	XXY/XXX	100	Cross‐sectional, comparison with controls matched on chronological age and maternal education level
Van Rijn & Swaab, 2015	XXX/XXY	53	Cross‐sectional, comparison with controls
Samango‐Sprouse et al, 2018	XXY (NL)	55	Cross‐sectional, comparison with normed reference group
	XXY (United States)	91
Ross et al, 2015	XYY	35	Cross‐sectional, comparison with controls matched on chronological age
Van Rijn et al, 2014a	XXX/XXY	53	Cross‐sectional, comparison with controls
Van Rijn et al, 2018	XXY	24	Cross‐sectional, comparison with normed reference group
Van Rijn et al, 2014b	XXX/XXY	49	Cross‐sectional, comparison with controls

^aPercentage prenatal diagnosed is not explicitly stated in this summary overview.