There is absolutely no reason for these companies to collect your PII whatsoever. You should go to nearest pharmacy and buy sterile swab, swab yourself and write long random number on it and send it. Once a month company publishes one giant zip with all the monthly result where you find your file by that random number you wrote.
The film Gattaca covers how this could lead to a sort of night are society pretty well, I highly recommend it.
It also makes it much much harder to use the data for clinical research.