Unidentified bright objects on brain MRI in children as a diagnostic criterion for neurofibromatosis type 1

Mathematical learning disabilities in special populations: phenotypic variation and cross-disorder comparisons

What is mathematical learning disability (MLD)? The reviews in this special issue adopt different approaches to defining the construct of MLD. Collectively, they demonstrate the current status of efforts to establish a consensus definition and the challenges faced in this endeavor. In this commentary, we reflect upon the proposed pathways to mathematical learning difficulties and disabilities presented across the reviews. Specifically we consider how each of the reviews contributes to identifying the MLD phenotype by specifying the range of assets and deficits in mathematics, identifying sources of individual variation, and characterizing the natural progression of MLD over the life course. We show how principled comparisons across disorders address issues about the cognitive and behavioral co-morbidities of MLD, and whether commonalities in brain dysmorphology are associated with common mathematics performance profiles. We project the status of MLD research ten years hence with respect to theoretical gains, advances in methodology, and principled intervention studies.

Potential influences on mathematical difficulties in children and adolescents with neurofibromatosis, type 1

Neurofibromatosis, type 1 (NF-1) is a common genetic disorder affecting 1 in 3,500-4,000 individuals in the world. Mutations of the NF-1 gene produce a myriad of physical, medical, and psychological manifestations. Although there is a very high degree of variability in the manifestations between individuals with NF-1, the majority of children and adolescents with NF-1 encounter difficulties that negatively impact their educational attainment. NF-1 is associated with a very high incidence of cognitive deficits and learning disability, sometimes including mathematical learning disabilities (MLD). A number of possible inter-related etiologies for MLD specific to children and adolescents with NF-1 are discussed, including the high incidence of attention deficit hyperactivity disorder, visual spatial impairment, morphological and functional brain abnormalities. Thus NF-1 exemplifies the wide ranging sources of potential influences on mathematical learning and MLD.