The neuropsychological phenotype of Chediak-Higashi disease

Table 3 T-scores (M = 50, SD = 10) on formal neuropsychological tests

	n	Mean (SD)	Percent scoring in bottom 16th percentile of population	Percent scoring in bottom 2.3 percentile of population
General Intelligence
Wechsler FSIQ^a	12	32.9 (8.1)	67%	42%
WRAT-4 Word Reading^a	12	40.1 (8.7)	42%	17%
WRAT-4 Spelling^a	8	44.3 (9.5)	38%	13%
WRAT-4 Math Computation^a	9	33.2 (6.0)	100%	22%
Executive Function
WCST Total Errors^a	9	30.6 (8.6)	100%	44%
WCST Perseverative Responses^a	9	34.6 (8.8)	56%	22%
Attention/Working Memory
WAIS-III Digit Span^a	13	45.9 (7.7)	15%	0%
WAIS-III Letter-Number Sequencing^a	10	40.1 (7.0)	40%	0%
CPT-II Omissions^b	9	19.0 (19.5)	78%	78%
CPT-II Commissions^b	9	42.7 (8.4)	22%	11%
CPT-II Reaction Time^b	9	38.3 (9.5)	67%	11%
CPT-II Reaction Time Standard Error^b	9	29.2 (15.6)	78%	56%
Processing Speed
WAIS-III Digit-Symbol Coding^a	13	31.5 (6.2)	86%	38%
WAIS-III Symbol Search^a	13	36.9 (5.2)	54%	0%
Language Fluency
COWA FAS^c	8	36.8 (7.0)	67%	13%
COWA Animals^c	8	35.0 (8.3)	50%	38%
Learning and Memory
NAB Memory Index^a	12	26.4 (12.3)	83%	75%
BVMT-R Learning^a	5	23.2 (7.7)	100%	80%
BVMT-R Memory^a	5	25.2 (10.1)	80%	80%
HVLT-R Learning^a	7	25.1 (8.1)	86%	86%
HVLT-R Memory^a	7	28.4 (9.0)	71%	57%
Psychomotor Speed
Grooved Pegboard (dominant)^c	8	16.4 (9.3)	100%	100%
Grooved Pegboard (nondominant)^c	8	15.4 (9.8)	100%	100%

^a T-score demographically corrected for age only
^b T-score demographically corrected for age and gender
^c T-score demographically corrected for age, education, race, and gender
FSIQ scores were linearly transformed from standard scores to T-scores based on the normal distribution. T-scores on the CPT-II were scored so that lower T-score reflect greater inattention (i.e., scoring program-derived output was transformed via the formula 50 - (score-50))

ISSN: 1750-1172