As others have said, HD is usually not diagnosed until well after you have children. Also, some people can be carriers without actually exhibiting symptoms. It

As others have said, HD is usually not diagnosed until well after you have children. Also, some people can be carriers without actually exhibiting symptoms. It goes like this: 1 - There's a particular sequence of bases that are repeated a certain number of times on a certain chromosome 2 - Below 25 repeats: normal, no HD 3 - 25~35 repeats: no HD but there's a risk of spontaneous increase when generating sperm/ovules 4 - 35+ you have HD with more repeats meaning earlier onset and faster progression My wife's mother has 40 repeats so she's on the milder side of the spectrum(age of onset ~50 and progression is steady but somewhat slow compared to her brother who started at 38) Individuals in the 25~35 repeats bracket can have children with HD(especially fathers since it seems that there's a higher incidence of increase for them, for some reason) In our case, my wife tested for this specifically once we seriously started considering the possibility of marriage and children. I'd decided I'd marry her regardless of the outcome but children were a different question altogether, so in that way I do agree with you, but it's definitely not a solution to the problem in the broad case of HD, but in individual cases where it is known to run in the family some people may choose to not have children if they are diagnosed at an early enough age. That being said, most people would prefer not to know if they have it when a parent is diagnosed, only ~5% of people at risk actually test for it with the vast majority preferring to live in denial. Humans are weird like that, but having seen firsthand what this did to my wife and her family when her mother was diagnosed I don't think I can really blame someone for not wanting to know. You can't make judgements about something like that until you've been in their shoes