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Silver Russell Syndrome

Clinical Features

The Silver-Russell syndrome is characterized by pre- and postnatal dwarfism with macrocephaly relative to body size. At birth, body size is on average 43 cm and body weight approx. 1900 g.

Typical craniofacial features include broad prominent forehead with a small triangular face and a small narrow chin. Stature remains small after birth and 50% of the patients develop some kind of body asymmetry. Affected children are gracile, often have a small thorax and frequently muscular hypotonia. Most patients show normal mental development, however, there is a risk of usually mild developmental delay (both motor and cognitive).

Genetic Information

Silver-Russel syndrome is a genetically heterogeneous condition. About 10% of the cases are caused by maternal uniparental disomy for chromosome 7 (UPD7 mat). Symptoms are caused by the absence of paternally contributed genes on chromosome 7.

Mostly, the Silver-Russell is of sporadic nature; however, families with autosomal dominant, autosomal recessive and X-linked inheritance have been described. In single cases, structural abnormalities of chromosomes were detected in Silver-Russell patients. The recurrence risk in case of a maternal UPD 7 is below 1%.

Prevalence

Rare

 

Diagnostic

 

Indication

Patients with pre- and postnatal dwarfism, especially with body asymmetry and corresponding dysmorphic signs

Method

Step1: Methylation specific PCR of 11p15

Step 2: Facultative: Confirmation of a maternal UPD7 using polymorhic markers

Sample Requirement

2 to 4 ml of EDTA blood from patients and parents

Duration

1 - 2 weeks



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