Russell-Silver Syndrome Life Expectancy

Russell-Silver syndrome (also called Silver-Russell syndrome, or SRS) is not considered life-threatening. Cleveland Clinic describes it as a lifelong condition without life-threatening effects, and says early, effective treatment is linked to a typical life expectancy. There are no large long-term studies of survival, though. The main health concerns in adults are shorter height and a higher risk of metabolic problems such as raised blood pressure, high cholesterol and type 2 diabetes. Regular check-ups can catch these.

What is known about adults with SRS

Most research on SRS has been in children. One of the few studies of older people followed 33 people with a genetically confirmed diagnosis, aged 13 to 69 (median age about 30). It was published in the Journal of Medical Genetics in 2020. The researchers found:

The same study found that quality of life was close to that of healthy adults, with a median life satisfaction score of 8 out of 10. Height didn't affect it. Forty per cent had a university degree. The authors concluded that the metabolic problems need more research and monitoring.

Health issues that need watching

In childhood:

• Low blood sugar (hypoglycaemia). Some children have repeated episodes. It is managed with frequent meals, extra calories and complex carbohydrates. Growth hormone also lowers the risk.
• Feeding problems and reflux. These are common. Smaller, more frequent meals, keeping a baby upright during feeds and acid-reducing medicine can help. A feeding tube is sometimes needed.
• Development. Some children have delayed motor skills, speech and language problems or learning difficulties.

In adulthood, Cleveland Clinic lists these as risks that can appear with age:

• metabolic syndrome (a cluster including high blood pressure, high blood sugar and abnormal cholesterol)
• low muscle mass and low bone density
• low sex drive
• testicular cancer
• a movement disorder that causes quick, involuntary movements

Because of these risks, adults with SRS benefit from regular checks of blood pressure, blood sugar and cholesterol.

Treatment

• Growth hormone can improve growth, body composition, motor development and appetite. It also reduces the risk of low blood sugar.
• Nutrition support helps a child reach their calorie needs safely.
• Therapy and educational support helps with speech, motor or learning difficulties.

Signs and features

SRS causes slow growth before and after birth. Typical features are:

• low birth weight
• a head that is normal in size but looks large for the body
• a small, triangular face with a prominent forehead and narrow chin
• sometimes one side of the body is larger than the other

Signs vary widely, so some people are diagnosed late or not at all.

How common is it and what causes it?

Estimates range from about 1 in 15,000 to 1 in 100,000 births. MedlinePlus gives 1 in 30,000 to 1 in 100,000.

Most cases are caused by changes on chromosome 11 that affect how growth genes such as H19 and IGF2 are switched on. A smaller number happen when both copies of chromosome 7 come from the mother. In 30–40% of people, no cause is found. Most cases are new (de novo) events, and the condition rarely runs in families.

Other names

The condition is also known as Silver-Russell syndrome, Russell-Silver syndrome, RSS and SRS.