Comparison of twins (40 identical and 23 fraternal) for mathematics deficits (MD), in which at least one member had a mathematics disability, found evidence for a significant genetic etiology. However, tests for the differential etiology of MD as a function of reading performance level were nonsignificant. (Author/DB)

This study examined whether indicators of math learning disability were observed in 35 5- and 6-year-olds with either neurofibromatosis, Turner Syndrome, or fragile X syndrome and compared to controls. Findings indicate that girls with fragile X or Turner syndrome but not neurofibromatosis are significantly more likely to have specific math…

Data from 148 identical and 111 fraternal twin pairs in which at least 1 member had a reading disability were statistically analyzed. Results suggest that genetic and shared-environment influences both contribute to the observed covariance between reading and mathematical deficits. (Author/DB)

Pedigree analysis of 12 young adults (9 of whom had learning disabilities) indicated that learning disability (LD) was strongly familial but that the type of disability (reading or math) was not directly inherited. Autoimmune disorders were significantly correlated with LD. In seven of the LD families, adults failed to overcome earlier reading and…

This study provides support for a potential subclinical marker in the executive function domain of siblings (n=18, ages 8-18) of autistic individuals, compared to learning-disabled controls. No group differences in theory-of-mind abilities were found. The need to develop more sensitive measures is discussed. (Author/JDD)

Word recognition data from identical and fraternal twins and siblings (N=172) indicated that the phonological coding deficit of children with reading disabilities was highly heritable. Orthographic coding was not significantly heritable. Poor readers with low IQs were superior to similar reading but average IQ readers in phonological coding.…

This article integrates the literature on intelligence and achievement outcomes in boys with Klinefelter syndrome (KS). It reports results of a study following 36 boys with KS and 33 sibling controls. Boys with KS demonstrated verbal cognitive deficits and significant underachievement in reading, spelling, and arithmetic, which increased with age.…