wontonstew t1_ivsv27k wrote

Not necessarily, some populations from particular regions or ethnicities can carry it without it being expressed ever before.

I got my genetic testing done, and I'm an autosomal recessive carrier for "Sandhoff disease". It's rare, and nobody in my family has ever had it going back generations, 1 in 500,000 chance of my kid having it. But what's super interesting to me is this.

It's only found in Canadian midwest native Americans, the creole people of Argentina, and Lebanon. Kind of crazy, right?

Now, if I lost the genetic date pool lottery, and happened to fall in love with someone else that also was a carrier? 50% chance my kid would actually have the disease.