Cognitive abilities of 20 boys and 5 girls, aged 6 to 11 years, with Silver-Russell syndrome were investigated at the Prince of Wales Hospital, Shatin, Hong Kong, the Institute of Child Health, and Middlesex Hospital, London, UK. The mean full scale IQ was 86, and 32% scored <70. Reading comprehension was 24 months below chronological age in 40%. Speech therapy was required in 48%. IQ scores were positively correlated with growth in head circumference. 
COMMENT. Features of Silver-Russell syndrome include low birth weight, short stature, body asymmetry, clinodactyly, and craniofacial dysmorphism - small triangular face, large forehead, small chin, shark’s mouth, and low set ears. The present study adds cognitive disorders to the list of features. Intrauterine growth retardation of Silver-Russell syndrome beginning early in pregnancy results in reduction in both birth weight and length. In this “symmetrical” type of growth retardation, in utero brain development is more likely to be affected than when growth retardation begins late in pregnancy.