Definition of Russell-Silver syndrome:

Russell-Silver syndrome is a disorder present at birth that involves poor growth, low birth weight, short height, and differences in the size of the two sides of the body.

Causes, incidence, and risk factors:

It is estimated that 7-10% of patients with this syndrome have a defect in a gene called the maternal uniparental disomy (UPD) for chromosome 7. However, a cause can not be identified for most patients. Most cases occur in a person whose family has no history of the disease.

The features associated with Russell-Silver syndrome have been linked to many other genetic problems such as:

• Chromosome rearrangements
• Autosomal dominant and recessive families (rarely reported)
• Abnormal methylation of chromosome 11p15

The estimated number of people who develop this condition varies greatly. Some say it affects about 1 in 3,000. Other reports say it affects 1 in 100,000 people. Males and females are equally affected.