The thrombocytopenia-absent radius (TAR) syndrome is characterised by bilateral absence of the radius with both thumbs present (absent thumbs suggests other syndromes) and thrombocytopenia which may be transient and tends to remit in later childhood but is usually symptomatic in early infancy (90% within the first 4 months). The main conditions which might be mistaken for TAR syndrome are Holt-Oram syndrome, Roberts syndrome, Fanconi anaemia, thalidomide embryopathy, and Rapadilino syndrome. TAR …