RESUMO
In this article the general and specific cognitive impairments of the boy R.H. with a de novo deletion 22q11.2 are described. His full-scale IQ was 73, and he obtained only slightly better verbal than non-verbal subtest scores. Neuropsychological assessment revealed specific impairments in perceptual categorization of objects presented suboptimal, matching of unfamiliar faces, and verbal learning and memory. In contrast, he performed in accordance with his intelligence level on other visual perceptual tasks, on non-verbal learning and memory tasks, and on attention tasks. Voxel-wise statistical comparison of a high-resolution T1-weighted magnetic resonance image of R.H's brain with similar images obtained from 14 normal control children revealed as major abnormalities a reduction of the right inferior parietal and superior occipital lobe, and a bilateral reduction of deep white matter behind the inferior frontal gyrus. These cognitive impairments and MRI abnormalities are not commonly described in 22q11.2 Deletion Syndrome and may indicate a larger heterogeneity in the neurocognitive phenotype than currently evidenced. At least in this boy the microdeletion seems to have interfered with the development and functioning of particular neural subsystems, while the structure and functioning of other subsystems was left intact.
