. 2017 Jan 12;31(3):255–267. doi: 10.1037/neu0000337

Table 1. Demographic Information, Metabolic Control, and General Cognitive Performance for 30 Control and 37 PKU Participants.

Variable	Controls		PKU participants		Controls vs. PKU
Variable	M	SD	M	SD	Controls vs. PKU
Note. Blood Phe measured in μmol/L. Impaired= > 2 z scores from control means. PKU = phenylketonuria; Phe = Phenylalanine.
Age	27.6	7.4	27.5	7.3	t_{(1, 65)} = 0.08; p = .94
Education years	15.2	1.7	14.4	1.9	t_{(1, 65)} = 1.6; p = .12
Gender (M/F)	10/20		13/24		χ₍₁₎² = .02; p = .88
Childhood (mean N obs. = 197; SD = 165)
Phe average			432	243
Phe fluctuation (SD)			205	63
Adolescence (mean N obs. = 77; SD = 70)
Phe average			721	340
Phe fluctuation (SD)			157	58
Adulthood (mean N obs. = 65; SD = 74)
Phe average			802	324
Phe fluctuation (SD)			137	68
Lifetime (mean N obs. = 340; SD = 241)
Phe average			634	291
Phe fluctuation (SD)			164	58
Current Phe			720	343
Cognitive performance
FIQ	113.8	10.9	103.9	14.3	t_{(1, 65)} = 3.1; p = .003
VIQ	112.2	10.2	102.3	12.9	t_{(1, 65)} = 3.1; p = .001
PIQ	112	11.7	104.5	15.1	t_{(1, 65)} = 2.2; p = .03
Overall z score	.0	.3	.5	.7	t_{(1, 65)} = −3.8; p < .001
Impaired participants
N	0		2
%	0		5.4
Impaired measures (%)	3.8	3.7	13.2	15.1	t_{(1, 65)} = −3.4; p = .001
Impaired participants
N	1		14
%	3.3		37.8		χ₍₁₎² = 11.35; p < .001