FMR1 and essential thrombocythemia: As such, the clinical features of the ET cases in our study resembled those of FXTAS more closely than previous similar studies; in those studies, FMR1 premutation was screened for in large groups of ET patients without further restricting phenotype (Clark et al., 2015; Deng et al., 2004; Garcia Arocena et al., 2004).