PICALM and Tremor: Moreover, genetic analysis of Clth/Clth mice derived from Clth/+ intercrosses and showing a continuous tremor refined the non-recombinant region to 1.37 Mb between the markers D15Mit97.2 and D15Mit246. Additional genotyping of non-affected (non-tremoring) mice from Clth/+×Clth/+ intercrosses yielded two more recombinants that further refined the region to 1.2 Mb between the markers D15Mit97.2 at 100.63 Mb and rs8266857 at 101.83 Mb (Fig. 1a).