Clinical characteristics and chromosome 11p15 imprinting analysis of Silver-Russell syndrome - a Chinese experience

Background: Silver-Russell syndrome (SRS) is an imprinting defect disease. This is the first study of Chinese children with SRS caused by chromosome 11p15 imprinting defects. Methods: Twenty-five SRS cases, diagnosed in Beijing Children's Hospital from 2006 to 2012, were studied retrospectively to detect chromosome 11p15 imprinting defects. Results: Over 80% of the children had (i) small for gestational age and postnatal growth retardation (mean height standard deviation score [HT SDS] was -3.56), (ii) mean body mass index (BMI) SDS was -2.10, and (iii) skeletal malformation. Chromosome 11p15 imprinting defects were examined in 16 of the 25 patients. Six had hypomethylation in chromosome 11p15 imprinting control region 1 (ICR1) of the paternal allele; one had hypomethylation in chromosome 11p15 ICR1 and hypermethylation in imprinting control region 2 (ICR2). Another patient had a duplicated maternal chromosome 11p15 fragment. Six patients had been treated with for 3-24 months. Growth rates ranged from 4 to 10.8 cm/year. Conclusions: This study demonstrated that Chinese children with SRS had more growth retardation than bone retardation, severely low levels of BMI, triangular faces, and limb asymmetry. Chromosome 11p15 imprinting defects contributed to 50% of these cases, and ICR1 hypomethylation was associated with asymmetry.