Polydactyly in a boy with Smith-Magenis syndrome

Smith-Magenis syndrome is a microdeletion syndrome involving chromosome 17p11.2. The characteristic features include mental retardation, dysmorphic facial features, minor skeletal anomalies including brachydactyly and behavioural abnormalities, such as disturbed sleep pattern, restlessness and self-destructive behaviour. We present a patient with this syndrome and with six digits on each hand. Polydactyly has not yet been described in Smith-Magenis syndrome as far as we know.