Silver-Russell dwarfism
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Silver-Russell dwarfism, also called Silver-Russell syndrome (SRS) or Russell-Silver syndrome (RSS) is a growth disorder occurring in approximately 1/75000 births. In the United States it is usually referred to as Russel-Silver Syndrome, and Silver-Russell Syndrome elsewhere. It is one of 200 types of dwarfism and one of five types of primordial dwarfism and is one of the few forms that is considered treatable. Its exact cause is unknown, but present research points toward a genetic component, possibly following maternal genes. There is no statistical significance of the syndrome occurring in males or females.
[edit] Diagnosis
Although confirmation of a specific genetic marker is in a significant number of individuals, there are no tests to clearly determine if this is what a person has. The Syndrome is usually caused by an mUPD on chromosome 7, in 7% of the cases. Which is an imprinting error where the person receives two copies of chromosome 7 from the mother (maternally inherited). As a 'Syndrome' a diagnosis is typically given for children upon confirmation of the presence of several 'symptoms' listed below.
Symptoms are Intrauterine Growth Restriction (IUGR) combined with some of the following:
- Often a diagnosis of Small for Gestation Age (SGA) at birth (Birth Weight Less than 2.8kg).
- Feeding problems: the baby is uninterested in feeding and takes only small amounts with difficulty.
- Excessive sweating as a baby, especially at night, and a greyness or pallor of the skin. This may be a symptom of low blood sugar (hypoglycemia).
- Triangular shaped face with a small jaw and a pointed chin. The mouth tends to curve down.
- A blue tinge to the whites of the eyes in younger children.
- Head appears large: the head circumference may be of normal size, which means it can appear large in comparison to a small body size.
- Wide and late-closing fontanelle.
- Clinodactyly: the little finger on each hand may be small and curve inwards.
- Body asymmetry: one side of the body grows more slowly than the other (Truncal, Cranal, and limb asymmetry).
- Continued poor growth with no "catch up" into the normal centile lines on growth chart.
- Precocious puberty (occasionally).
- Low tone.
- Gastroesophogeal Reflux.
- Usually Sporadic
- A Striking lack of subcutaneos fat
[edit] Treatment
Growth hormone therapy is often prescribed as part of the treatment of SRS. The hormones are given by injection typically daily from the age of 2 years old through teenage years. It may aid growth even in cases where the patient does not have a growth hormone deficiency, and medical practitioners currently believe it can also help with other related issues such as blood sugar levels. Treatment results vary depending on dosage and the beginning age of treatment. Typically growth hormone therapy will not guarantee the child reaches their "full" height potential, but significantly more than without it. Side effects include an increase in muscle tone and irregular bone growth. It is unknown if SRS and growth hormone deficiency are linked.
