WAGR syndrome is a rare genetic disorder characterized by Wilms tumor, aniridia, genitourinary anomalies and mental retardation. The syndrome is caused by heterozygous contiguous gene deletions of variable size on chromosome 11, involving a region that encompasses more than 100 genes, many of which have unknown function in humans. In our preliminary studies, we have observed that approximately two-thirds of patients with WAGR syndrome have deletion of the gene which encodes brain-derived neurotrophic factor (BDNF), and that BDNF haploinsufficiency is associated with obesity and with parent reports of hyperphagia and impaired nociception, suggesting that BDNF may play an important role in human energy balance as well as pain sensation. We now propose to conduct a comprehensive clinical phenotype-genotype study on patients with WAGR syndrome and other 11p deletions. We plan to enroll 75 subjects with WAGR syndrome/11p deletions who will undergo evaluations of the following systems: metabolic/endocrine, sensation/nociception, ophthalmologic, audiologic, neurocognitive, renal/genitourinary, oncologic, dental/craniofacial, cardiac, and orthopedic. Genetic testing will be performed on the parents of subjects with WAGR syndrome/11p deletion who choose to participate in order to determine if parental origin of the deletion influences phenotype. We also plan to enroll 75 healthy subjects as body-size matched controls for metabolic studies and 75 patients with isolated aniridia as visually impaired controls for neurocognitive studies. We hypothesize that a more complete understanding of the correlation between phenotype and genotype could lead to improved medical care of these patients through genotype-specific management as well as yield further insight into the physiological role of genes in the 11p region.