For as little as $1,000 and a saliva sample, customers will be able to learn what is known so far about how the billions of bits in their biological code shape who they are. Three companies have already announced plans to market such services, one yesterday.

Offered the chance to be among the early testers, I agreed, but not without reservations. What if I learned I was likely to die young? Or that I might have passed on a rogue gene to my daughter? And more pragmatically, what if an insurance company or an employer used such information against me in the future?

But three weeks later, I was already somewhat addicted to the daily communion with my genes. (Recurring note to self: was this addiction genetic?)

For example, my hands hurt the other day. So naturally, I checked my DNA.

Was this the first sign that I had inherited the arthritis that gnarled my paternal grandmother’s hard-working fingers? Logging onto my account at 23andMe, the start-up company that is now my genetic custodian, I typed my search into the “Genome Explorer” and hit return. I was, in essence, Googling my own DNA.Last month, alone in a room at 23andMe’s headquarters in Mountain View, Calif., with my password for the first time, I wavered (genetic?) and walked down the hall to get lunch.

Once I looked at my results, I could never turn back. I had prepared for the worst of what I could learn this day. But what if something even worse came along tomorrow?

Some health care providers argue that the public is unprepared for such information and that it is irresponsible to provide it without an expert to help put it in context. And at times, as I worked up the courage to check on my risks of breast cancer and Alzheimer’s, I could see their point.

One of the companies that plans to market personal DNA information, Navigenics, intends to provide a phone consultation with a genetic counselor along with the results. Its service would cost $2,500 and would initially provide data on 20 health conditions.

I knew I would never be able to pass up the chance to fill in more pieces of my genetic puzzle.

But I had decided not to submit my daughter’s DNA for testing — at least not yet — because I didn’t want to regard anything about her as predestined. If she wants to play the piano, who cares if she lacks perfect pitch? If she wants to run the 100-meter dash, who cares if she lacks the sprinting gene? And did I really want to know — did she really want to know someday — what genes she got from which parent and which grandparent?