UNIPARENTAL DISOMY-7 IN SILVER-RUSSELL-SYNDROME AND PRIMORDIAL GROWTH-RETARDATION

Maternal uniparental disomy for the entire chromosome 7 has so far bee n reported in three patients with intrauterine and postnatal growth re tardation. Two were detected because they were homozygous for a cystic fibrosis mutation for which only the mother was heterozygous, and one because he was homozygous for a rare COL1A2 mutation. We investigated 35 patients with either the Silver-Russell syndrome or primordial gro wth retardation and their parents with PCR markers to search for unipa rental disomy 7, Four of 35 patients were found to have maternal disom y, including three with isodisomy and one with heterodisomy. The data confirm the hypothetical localization of a maternally imprinted gene ( or more than one such gene) on chromosome 7. It is suggested to search for UPD 7 in families with an offspring with sporadic Silver-Russell syndrome or primordial growth retardation.