Genetics of Silver-Russell syndrome

The Silver-Russell syndrome (SRS) is generally sporadic, but with sufficient reported cases of dominant and recessive patterns of inheritance to suggest a genetic cause in some cases, at least. No consistent cytogenetic abnormalities have been found although some features of the syndrome have been reported to be associated with structural abnormalities of distal 15q. More recently it has been shown that about 10% of SRS patients have maternal uniparental disomy of chromosome 7 which suggests the presence of a maternally imprinted gene on chromosome 7 that is associated with SRS. In the majority of patients with normal biparental inheritance of chromosome 7 the same gene could be involved if the paternal copy were deleted or mutated so that it is disabled and the maternal copy is silent because of the imprinting.