I would research Fragile X Syndrome, as the silent carriers of the gene develop FXTAS (Fragile X tremor Ataxia Syndrome) characterized by essential tremors beginning earlier than other neurodegenerative diseases.

I am a carrier. my gene lines are Hathorne-Bicknell-Hobart-Wade-Dawes-Smith.... absolutely either Sherman Hathorne or Carrie Hobart Bicknell Wade