Our previous investigations have identified 27 familial ET patients with NOTCH2NLC pathogenic expansions and 3 with GIPC1 pathogenic expansions, all lacking intermediate repeats in the two genes.6,28 Herein, we compared carriers of tremor-associated pathogenic expansions with those of NOTCH2NLC and GIPC1 expansions. This evidence concerns the gene GIPC1 and essential thrombocythemia.