Estimated at around 30 years, it's accepted as the average period between birth of parents & their offspring
However
, resemblance between spouses for ADHD symptoms has not yet... [DOC] [TLE] Huntington's Disease Genetics - NCBI - National Institutes of Health [PAR] Survival from onset to death averages 1720 years with some evidence that later 
onset is ... An estimates of 6% has been offered., Repeats between 36 and 39 are 
also rare (2.7% in ... Normal and expanded HD repeat sizes.