First Genetic Screening for Maternal Uniparental Disomy of Chromosome 7 in Turkish Silver-Russell Syndrome Patients

Objective: Silver–Russell syndrome (SRS) is a clinically and genetically heterogeneous syndrome which is characterized by severe intrauterine and postnatal growth retardation, and typical characteristic facial dysmorphisms. It has been associated with maternal uniparental disomy (UPD) for chromosome 7 and hypomethylation of imprinting control region 1 (IGF2/H19) in 11p15. UPD refers to the situation in which both copies of a chromosome pair have originated from one parent. UPD can be presented both as partial heterodisomy and isodisomy. The aim of this study was to determine the maternal UPD7 (matUPD7) in 13 Turkish SRS patients.
Methods: Genotyping for matUPD7 was performed with microsatellite markers by polymerase chain reaction.
Findings: The maternal UPD7 including the entire chromosome was identified in 1/13 (7.6 %) of individuals within SRS patients. There were no significant differences between clinical features of matUPD7 case and other SRS cases except congenital heart defects.
Conclusion: It is often difficult to establish diagnosis of a child with intrauterine growth retardation (IUGR), growth failure and dysmorphic features. Thus, screening for matUPD7 in IUGR children with growth failure and mild SRS features might be a valuable diagnostic tool.

Keywords
Silver–Russell Syndrome; Maternal UPD7; Microsatellite Markers; Intrauterine Growth Retardation