LANGUAGE AND READING DEFICITS ASSOCIATED WITH NEUROFIBROMATOSIS TYPE-1 - EVIDENCE FOR A NOT-SO-NONVERBAL LEARNING-DISABILITY

Neurofibromatosis Type 1 (NF1) is a common genetic disorder for which nonverbal learning disability (NLD) is frequently reported. In this st udy, verbal and nonverbal skills among NF1 school-age children and the ir unaffected siblings were assessed. Results of matched-paired compar isons were consistent with previous reports of visuospatial deficits i n NF1. The results also indicate verbal weaknesses in NF1, including d eficits in vocabulary and phonological awareness, and a positive corre lation-among the NF1 group only - between performance on the Judgment of Line Orientation test (Benton, 1983) and several verbal tasks. The verbal deficits indicate that NLD may not be an accurate construct wit h which to describe the NF1 phenotype. Children with NF1 manifested sk ills deficits in mathematics and reading even though the incidence of discrepancy-based reading disability (RD) or mathematics disability (M D) did not differ across groups. The NF1 profile illustrates the conce ptual difficulty underlying discrepancy-based RD because it appears th at the language disorder in neurofibromatosis influences both measures used (achievement and IQ) to calculate the discrepancy.