Children with chromosome 22q11.2 deletion syndrome (22q11.2DS), Fragile X 
syndrome (FXS), or Turner syndrome (TS) are considered to belong to distinct 
genetic groups, as each disorder is caused by separate genetic alterations. Even 
so, they have similar cognitive and behavioral dysfunctions, particularly in 
visuospatial and numerical abilities. To assess evidence for common underlying 
neural microstructural alterations, we set out to determine whether these groups 
have partially overlapping white matter abnormalities, relative to typically 
developing controls. We scanned 101 female children between 7 and 14years old: 
25 with 22q11.2DS, 18 with FXS, 17 with TS, and 41 aged-matched controls using 
diffusion tensor imaging (DTI). Anisotropy and diffusivity measures were 
calculated and all brain scans were nonlinearly aligned to population and 
site-specific templates. We performed voxel-based statistical comparisons of the 
DTI-derived metrics between each disease group and the controls, while adjusting 
for age. Girls with 22q11.2DS showed lower fractional anisotropy (FA) than 
controls in the association fibers of the superior and inferior longitudinal 
fasciculi, the splenium of the corpus callosum, and the corticospinal tract. FA 
was abnormally lower in girls with FXS in the posterior limbs of the internal 
capsule, posterior thalami, and precentral gyrus. Girls with TS had lower FA in 
the inferior longitudinal fasciculus, right internal capsule and left cerebellar 
peduncle. Partially overlapping neurodevelopmental anomalies were detected in 
all three neurogenetic disorders. Altered white matter integrity in the superior 
and inferior longitudinal fasciculi and thalamic to frontal tracts may 
contribute to the behavioral characteristics of all of these disorders.