An Examination of Lexical and Sublexical Reading Skills in Children with Neurofibromatosis Type 1

Abstract

Neurofibromatosis type 1 (NF1) is an inherited neurocutaneous disorder associated with a high frequency of cognitive and learning difficulties. Based on discrepancies between IQ and academic achievement, approximately 17% of children with NF1 have been classified as having reading impairments. In this study, the lexical and sublexical reading skills of children with NF1 (n = 30) were examined using the Castles' Word/Non-Word Test (modified version), together with measures of neuropsychological functioning and academic achievement. Twenty children (67%) demonstrated deficits in one or more reading subskills, with 75% of these meeting criteria for phonological dyslexia and 20% classified with mixed dyslexia. These findings indicate that a large proportion of children with NF1 may be characterized by a specific difficulty with the sublexical procedure, suggesting a difficulty employing spelling-to-sound rules to assemble a pronunciation when reading. In line with previous studies, the present findings also suggest that discrepancy-based methods may not be sufficiently sensitive to identify children who experience reading difficulties.

Keywords:

• Reading
• Lexical and sublexical reading
• Castles' Word/Non-Word Test
• Neurofibromatosis
• Dual-route model of reading

The authors wish to acknowledge Dr. Belinda Barton for her helpful and timely statistics advice. The authors would also like to acknowledge Jennifer Irle and Jennifer Lorenzo for their assistance with testing and helpful comments in the preparation of this manuscript.