Russell-Silver syndrome

Alternative names

Silver-Russell syndrome; Silver syndrome

Definition

Rusell-Silver syndrome is a congenital disease (present at birth) characterized by short stature and, frequently, asymmetry in the size of the two halves or other parts of the body.

Causes, incidence, and risk factors

Genetic problems are thought to cause this syndrome, although the specific gene(s) remain to be discovered. The pattern of inheritance has not been determined, but in most cases it seems to occur without any family history of the condition.

Children with Russell-Silver syndrome are born small and generally achieve less than 5 feet at adult height. Side-to-side asymmetry is fairly common. For example, a left body part may be larger than the right counterpart. This asymmetry may occur anywhere including the face.

Other characteristics include excessive sweating, a small triangular face that makes the skull look large by comparison, inward curving 5th fingers, and colored spots on the skin called cafe-au-lait spots.

Symptoms

• slow growth before birth
  
• short stature throughout childhood and at final height
  
• cafe-au-lait (coffee with milk) colored spots
  
• severe feeding problems in childhood (reflux disease, food aversion, failure to thrive)
  

Signs and tests
A physical examination may show:

• delayed closure of anterior fontanel (soft spot)
  
• side to side asymmetry (especially limbs)
  
• curved-in fifth finger (clinodactyly)
  
• normal intelligence
  
• small or "pushed-back" jaw (micrognathia or retrognathia )
  
• small triangular face with normal head circumference
  

Tests include:

• A glucose tolerance test may show episodes of low blood sugar when fasting.
  
• Skeletal X-rays may show a discrepancy (delay) between "bone age" (the age that the bones appear) and the actual age or sexual development.
  
• A karyotype (examination of a person's chromosomes under a microscope) is frequently ordered. About 10% of patients will have 2 copies (instead of 1) of their mother's chromosome 7 (a situation called maternal uniparenal disomy). Rarely, duplication of genes in a certain area of the chromosome 7 inherited from the mother is seen.