Dad had als @ 62, mom has dementia @ 67. i am worried about my genetics. i'm healthy and family history beyond parents is clear. am i being paranoid?

Probably: Genetic factors of ALS and frontotemporal dementia are not clear but I do not think that you should worry.

Do what you can: We don't know the genetics of frontotemporal dementia and als. Prevent dementia as best you can--no smoking, exercise regularly and vigorously, maintain a healthy weight, http://www.Helpguide.Org/elder/alzheimers_prevention_slowing_down_treatment.Htm eat colorful vegetables: http://www.Voanews.Com/content/eating-colorful-produce-may-help-prevent-als/1596650.Html.

Yes: anyone with onset of dementia in their 60's may have a form for which you have a 1 in 2 chance of inheriting. Your mother should be evaluated for these by a clinical geneticist who may provide a definitive diagnosis. After appropriate counseling, you could elect to be tested whether you have inherited the causative mutation. ALS is much less likely to be a risk for you. Keep tests confidential