Silver-Russell syndrome (SRS) or Russell-Silver syndrome (RSS) is a growth disorder occurring in approximately 1/3,000 to 1/100,000 births.
This is a condition characterised by poor growth before and after birth (birth weight usually less than 2.5 kg).
Other characteristics of SRS include:
- Commonly babies with SRS are uninterested in feeding and take only small amounts with difficulty.
- Low blood sugar (hypoglycemia)
- Excessive sweating as a baby, especially at night.
- Triangular shaped face with a small jaw and a pointed chin.
- A blue tinge to the whites of the eyes in younger children
- Head circumference may be of normal size and disproportionate to a small body size
- Wide and late-closing fontanelle (soft spot of the skull.
- A bend or curvature of the fifth fingers (the "little fingers") toward the adjacent fourth fingers called clinodactyly.
- Body asymmetry: one side of the body grows differently to the other
- Continued poor growth with no "catch up" into the normal centile lines on a growth chart
- Low muscle tone
- Gastroesophageal reflux disease (tendency to vomit)
- A striking lack of subcutaneous fat .
Genetic Causes
In approximately 60% of cases, SRS has been demonstrated to be due to a change in the expression (activation) of imprinted genes on chromosome 11 (for more information on imprinting and genetics please see the ‘Other imprinting disorders’ page). This is usually due to a problem with the ‘silencing’ of the copy of a gene from the father (paternal hypomethylation) on chromosome 11.
In approximately 10% of cases, SRS is caused by a maternal uniparental disomy (UPD) on chromosome 7. This is where the person receives two copies of chromosome 7 from the mother instead of the usual one from each parent.
Useful links for SRS:
References for Silver Russell Syndrome
- Gicquel C, Rossignol S, Cabrol S, Houang M, Steunou V, Barbu V et al. Epimutation of the telomeric imprinting center region on chromosome 11p15 in Silver-Russell syndrome. Nat Genet 2005; 37(9):1003-1007.
- Netchine I, Rossignol S, Dufourg MN, Azzi S, Rousseau A, Perin L et al. 11p15 imprinting center region 1 loss of methylation is a common and specific cause of typical Russell-Silver syndrome: clinical scoring system and epigenetic-phenotypic correlations. J Clin Endocrinol Metab 2007; 92(8):3148-3154.
- Fisher AM, Thomas NS, Cockwell A, Stecko O, Kerr B, Temple IK et al. Duplications of chromosome 11p15 of maternal origin result in a phenotype that includes growth retardation. Hum Genet 2002; 111(3):290-296.
- Eggermann T, Meyer E, Obermann C, Heil I, Schuler H, Ranke MB et al. Is maternal duplication of 11p15 associated with Silver-Russell syndrome? J Med Genet 2005; 42(5):e26.
- Eggermann T, Zerres K, Eggermann K, Moore G, Wollmann HA. Uniparental disomy: clinical indications for testing in growth retardation. Eur J Pediatr 2002; 161(6):305-312.