We all have harmful mutations

Occasional strange cases notwithstanding, every parent gives his or her biological child 50 percent of that child's DNA. And every one of us, regardless of zip code, membership in an executive health program, or religious affiliation, carries at least a handful of harmful mutations that may or may not manifest in us or in our children, should they inherit them as part of that 50 percent.

Misha Angrist, Here is a Human Being: At the Dawn of Personal Genomics (New York: HarperCollins, 2010), ch. 1 (Kindle loc. 162)