Table 1.

Participant characteristics

Variable	XXY/KS cohort		Test for difference		XYY cohort		Test for difference		XXY/KS vs. XYY
	XXY/KS probands	XY controls	Test statistic	p-value	XYY probands	XY controls	Test Statistic	p-value	Statistic	p-value
Sample size	102	74	-	-	64	60	-	-	-	-
Age (years)
Mean (sd)	16.2 (4.98)	17.1 (5.63)	t = 1.12	0.27	13.1 (6)	13.1 (5)	t = 0	1	t = 3.6	0.0005
Range	6–25	6–25	-	-	5–25	5–24	-	-	-	-
Full Scale IQ
Mean (sd)	92.8 (13.1)	115.0 (13.1)	t = 11.6	<.0001	86 (14)	117 (11)	t = −5.3	<0.0001	t = 3.14	0.0021
Range	64–127	83–146	-	-	53–112	88 – 144	-	-	-	-
SES
Mean (sd)	39.6 (18.6)	48.2 (20.7)	t = −2.9	0.005	53 (19)	39 (16) 20 – 77	t = 4.4	<0.0001	t = −1.44	0.153
Range	20–120	20–95	-	-	20–95	-	-	-	-	-
Gestation (weeks)
Mean (sd)	38.9 (1.85)	-	-	-	38 (2)	39.2 (2)	t = −2.9	0.0004	t = 1.64	0.104
Range	32.5–42	-	-	-	31–42	32 – 42	-	-	-	-
Birthweight (kg)
Mean (sd)	3.28 (0.47)	-	-	-	3.26 (0.6)	3.55 (0.5)	t = −2.8	0.006	t = 0.56	0.577
Range	1.8–4.5	-	-	-	1.6–4.5	2.5 – 4.7	-	-	-	-
Time of SCA diagnosis
Prenatal, n (%)	38 (37%)	-	-	-	25 (39%)	-	-	-	χ2 = 0.005	0.94
Postnatal, n (%)	64 (63%)	-	-	-	39 (61%)	-	-	-	-	-
Vineland Adaptive Behavior Composite Score (VABC)
Mean (sd)	77.4 (14.7)	-	-	-	76 (13)	-	-	-	t = .522	0.602
Range	41–111	-	-	-	42–112	-	-	-	-	-
Caregiver Strain Questionnaire Global Score (CSQ)
Mean (sd)	6 (2.39)	-	-	-	7.1 (2.79)	-	-	-	t = −2.57	0.012
Range	3–12.5	-	-	-	3–14.3	-	-	-	-	-