MECOM and Thrombocytopenia - absent radius: To provide an explanation for the skeletal abnormalities observed in TAR syndrome, Albers et al., [24] assumed that, in addition to a tissue-dependent effect, it is possible that the regulatory SNPs had developmental stage–dependent consequences keeping as an example the Mecom gene encoding Evi1 that is expressed in a transient manner in emerging limb buds in mouse [33].