Russell-Silver Syndrome

Epidemiology and Etiology:

• Unclear etiology in most cases
• 11p15 abnormalities (40-64%)
• Methylation defects
• Maternal duplications
• Mosaic, full maternal UPD11 has been reported in one patient
• upd(7)mat (10%)
• dup(7p) has been reported in 2 cases
• GRB10 included
• Imprinted
• Growth regulation
• GRB10 mutations in 2 patients

Common sites:

Gross features:

Histologic features:

Immunophenotype:

Marker:

Sensitivity:

Specificity:

Molecular features:

Other features:

• clinical features:
• prenatal and postnatal growth retardation
• asymmetric (head-sparing)
• triangular facies
• relative macrocephaly
• hemihypotrophy / asymmetry sometimes
• other dysmorphic features
• limb asymmetry sometimes
• bone age retardation
• mild developmental delay (~50%)

References:

• ACMG Statement on Diagnostic Testing for Uniparental Disomy (2001)
• Kotzot D. Prenatal testing for uniparental disomy: indications and clinical relevance. Ultrasound Obstet Gynecol. 2008;31(1):100-5.
• Dawson et al. CCMG Guidelines: Prenatal and Postnatal Diagnostic Testing for Uniparental Disomy (UPD). Clinical Genetics (in print, 2010)