Pedigrees with variants in the genes NOS3 (families a and b) KCNS2 (family c), HAPLN4 (family d) and USP46 (family e). Genetic pedigrees for families with likely pathogenic mutations are shown. The generation in each pedigree is indicated by roman numerals. The proband is indicated by an arrowhead. A ‘+' symbol indicates subjects that were exome sequenced. Below each subject with DNA available for genetic analysis, the subject id (00X), age at tremor onset and date of birth are indicated. Symbol shading is as follows: definite ET, symbols completely black; probable ET, symbols half vertical black fill; possible ET, symbols with a quadrant in black; and unaffected, clear symbol.