From Cortical and Subcortical Grey Matter Abnormalities to Neurobehavioral Phenotype of Angelman Syndrome: A Voxel-Based Morphometry Study.

Angelman syndrome (AS) is a rare neurogenetic disorder due to loss of expression of maternal ubiquitin-protein ligase E3A (UBE3A) gene. It is characterized by severe developmental delay, speech impairment, movement or balance disorder and typical behavioral uniqueness. Affected individuals show normal magnetic resonance imaging (MRI) findings, although mild dysmyelination may be observed. In this study, we adopted a quantitative MRI analysis with voxel-based morphometry (FSL-VBM) method to investigate disease-related changes in the cortical/subcortical grey matter (GM) structures. Since 2006 to 2013 twenty-six AS patients were assessed by our multidisciplinary team. From those, sixteen AS children with confirmed maternal 15q11-q13 deletions (mean age 7.7 ± 3.6 years) and twenty-one age-matched controls were recruited. The developmental delay and motor dysfunction were assessed using Bayley III and Gross Motor Function Measure (GMFM). Principal component analysis (PCA) was applied to the clinical and neuropsychological datasets. High-resolution T1-weighted images were acquired and FSL-VBM approach was applied to investigate differences in the local GM volume and to correlate clinical and neuropsychological changes in the regional distribution of GM. We found bilateral GM volume loss in AS compared to control children in the striatum, limbic structures, insular and orbitofrontal cortices. Voxel-wise correlation analysis with the principal components of the PCA output revealed a strong relationship with GM volume in the superior parietal lobule and precuneus on the left hemisphere. The anatomical distribution of cortical/subcortical GM changes plausibly related to several clinical features of the disease and may provide an important morphological underpinning for clinical and neurobehavioral symptoms in children with AS.

Functioning and disability in patients with Angelman syndrome: utility of the International Classification of functioning disability and health, children and youth adaptation framework.

PURPOSE: Angelman syndrome (AS) accounts for upto 6% of all cases with severe mental retardation and epilepsy. Clinical findings include developmental delay, severely impaired expressive language, ataxic gait, tremulousness of limbs and a typical behavioral profile including a happy demeanour, hyperactive behavior and low attention span. Seizures, abnormal electroencephalogram, microcephaly and scoliosis are observed in >80% of patients. Cognitive, language and orthopedic problems must be addressed with vigorous rehabilitation programs. Classification of functioning disability and health, children and youth adaptation (ICF-CY) can provide the most adequate framework to describe the condition of the persons towards whom rehabilitative efforts are concentrated. The aim of the study is to test whether the ICF-CY framework is effectively able to capture the various dimensions of health in AS. METHODS: We applied the ICF-CY, to the detail of second level codes, to a cohort of 11 patients with AS of various ages. The coding was obtained by the multi-professional team following these children for the rehabilitation program. RESULTS: The functional profile obtained applying the ICF-CY is complete and comparable with the characteristics of the syndrome described in literature. The possibility of highlighting not only the problems but also the points of strength appears as very helpful. The second level codes may be too broad to provide insight in the clinical and rehabilitative peculiarities, and the use of the full power of the classification may be more advisable for clinical use. CONCLUSIONS: This prelimiary study shows that ICF-CY is a valid tool to frame the clinical characteristics of a complex syndrome as AS, and may give a strong foundation for the rehabilitation programming.