The Turkish Journal of Pediatrics
2009 , Vol 51 , Num 6
Cognitive functions in neurofibromatosis type 1 patients and unaffected siblings
Departments of Pediatric Neurology, 1Hacettepe University Faculty of Medicine, Ankara, 3Ondokuz Mayıs University
Faculty of Medicine, Samsun, and 4Çukurova University Faculty of Medicine, Adana, and 2Department of Pediatrics,
Pamukkale University Faculty of Medicine, Denizli, Turkey
Attention, learning, and perceptual problems have been reported at various
degrees and rates in neurofibromatosis type 1 (NF1). We aimed to define the
cognitive profiles frequently associated with NF1. Children and adolescents
with NF1 (n=58) were tested using Wechsler Intelligence Scales for Children-
Revised (WISC-R), Judgment of Line Orientation, and Bender Visual-Motor
Gestalt tests. Comparison groups were unaffected siblings of NF1 patients
(n=20), children with attention deficit and hyperactivity disorder (ADHD,
n=40), and normal children (n=40). No difference was found between
familial or sporadic NF1 cases. Seventeen/58 (29%) of NF1 cases had a full
scale IQ <70. The subgroup of NF1 patients with full scale IQ>80 (n=27)
scored lower in WISC-R subtests measuring visual perception when compared
to a healthy control group of similar intelligence, and lower in arithmetic
but better in Bender-Gestalt and Judgment of Line Orientation tests when
compared to an ADHD group of similar intelligence. These results indicate a
high prevalence of mental retardation in a clinical NF1 series. NF1 patients
who have normal intelligence may have impaired visual perception, but
their visual perceptual problems are less than in ADHD. The tendency of
unaffected siblings of NF1 patients to have mildly but consistently low test
scores compared to healthy controls needs to be studied further for underlying
genetic or environmental factors.
Keywords :
neurofibromatosis type 1, NF1, cognitive, learning, mental.