Recurrent Rearrangements of Chromosome 1q21.1 and Variable Pediatric Phenotypes

This study shows an association between a broad range of phenotypes and either deletion or duplication of a genomic segment at chromosome 1q21.1, suggesting a fundamental role of the deletion or duplication in early development and challenging the notion that a specific mutation disposes toward a specific disorder or syndrome. This study shows an association between a broad range of phenotypes and either deletion or duplication of a genomic segment at chromosome 1q21.1, suggesting a fundamental role of the deletion or duplication in early development. Recent advances in technologies such as comparative genomic hybridization (CGH; see Glossary) allow for the routine detection of submicroscopic deletions and duplications. Several studies of persons with mental retardation or congenital anomalies of unknown cause have led to the identification of new genomic disorders. 1 – 10 Classically, criteria that have been applied to determine whether a given rearrangement is causative include de novo appearance of the deletion or duplication in an affected individual (i.e., it is not present in unaffected parents), recurrence of the same or an overlapping event in similarly affected persons, and absence of the deletion or duplication in . . .