Evaluation of phonological processing skills of young children with neurofibromatosis type 1

Specific learning disability (SLD) is characterized by deficits in one or several processes needed for understanding or using language, and includes the diagnosis of language learning disability or dyslexia (a reading disability subtype). Populations most at-risk for SLD include those with a history of speech sound disorder and receptive/expressive language delay, and concerns with either phonological processing or oral language comprehension. Preschool children with SLD can initially present with problems in word pronunciation, rhyming, word-finding, and/or following directions, and may obtain a diagnosis of speech sound disorder or language impairment. Children with speech sound disorder characterized by the use of phonological patterns may have poor or inaccurate underlying phonological representations. As the demands of the educational curriculum increase, difficulties in speech/language use may persist, with children subsequently securing a diagnosis of reading disability in the later elementary school years. In the preschool years, children with the neurocutaneous genetic disorder neurofibromatosis type 1 (NF1) may exhibit delays in speech and/or language. Approximately 30% to 65% of school-aged children with NF1 exhibit SLD. Currently, the nature of SLD in NF1 is unclear. Learning disability subtypes have varied across studies, depending on the populations included or the models or profiles utilized in the investigations. Hyman et al. evaluated 81 children with NF1 and found that 52% exhibited learning disability; 32% exhibited general learning disability, 8.6% exhibited reading disability, 8.6% exhibited spelling disability, and 9.9% exhibited mathematical disability (dyscalculia). Watt et al. evaluated 30 children with NF1 and found reading concerns in 67%; 75% of whom exhibited phonological dyslexia and 20% of whom exhibited mixed dyslexia. Orraca-Castillo et al. evaluated 32 children with NF1 and found SLD in 53.1%; dyslexia occurred in 50%, and dyscalculia occurred in 18.8%. Differences in auditory processing or functional cortical activity during phonological processing may contribute to SLD in this population. There is a need to evaluate the relationship between preliteracy and spelling abilities in 5to 6-year-old children with NF1 to elucidate possible precursors to SLD. As Arnold et al. suggest, deficits in phonological awareness, phonological memory, and letter-sound knowledge in young children with NF1 may play a role in how phonological information is stored and subsequently retrieved when decoding during reading and spelling. It is likely that phonological processing and deficits in phonics may account for later SLD in children with NF1. Arnold et al. are to be commended for conducting a study aimed at further characterizing the pre-literacy skills of young children with NF1. The nature of the investigation is timely given our knowledge of SLD in NF1. Results of the study support future clinical practice and the need for early assessment of phonological processing and phonics skills of young children with NF1. For children with identified concerns, timely follow-up with a speech-language pathologist is indicated. If speech-language concerns are remediated by the time children are approximately 51⁄2 years of age, literacy skills can develop fairly normally for those without NF1. Children without NF1 who exhibit speech sound disorder or language impairment have also shown improvements in response to phonological awareness intervention. Future research should investigate the effectiveness of speech-language intervention for young children with NF1 in this at-risk population.