Additional Information

Russell-Silver Syndrome (RSS) is a genetically heterogeneous imprinting disorder characterized by intrauterine growth retardation followed by postnatal growth deficiency. Affected individuals typically have a variable combination of proportionately short stature, triangular facies, fifth-finger clinodactyly, hemihypotrophy, and developmental delay. Alterations in DNA methylation of paternal imprinting center 1 (IC1), a region which lies upstream of the H19 gene on 11p15, can be seen in 35-50% of individuals with RSS. Duplication of maternal 11p15.5 is another cause of RSS in a small number of individuals. Chromosome 7 abnormalities have also been implicated in RSS. Maternal uniparental disomy for chromosome 7 (UPD7) accounts for an additional 10% of RSS cases; other changes, such as deletions/duplications with chromosome 7, have also been seen but are rare. In approximately 40% of patients with clinical features of RSS, a molecular alteration cannot be identified.