DEAR ABBY: I recently had major surgery. After the operation, my surgeon advised me that I had a genetic defect which had complicated the procedure. He advised me to notify my children so they could be checked for it.

I notified my four children and they all have a similar problem. Here is my dilemma:

When I was in college, I foolishly had an affair with an older man and became pregnant. I couldn't support a child at that time, so I chose to give my son up for adoption. Because of my genetic defect, I decided to attempt to locate this child to let him know about it. I hired a private detective who soon located him, but his adoptive mother had told him I died shortly after he was born.

When I married him 30 years ago, my husband knew I'd had a child, but the subject has been taboo ever since our wedding. None of my children know they have a half-brother.

Should I contact my son even though he thinks his birth mother is dead? I'm sure it would be upsetting to learn that his adoptive mother lied to him. He may need to know about the problem that runs in our family. Please advise me. -- TORN IN TOLEDO

DEAR TORN: Since the information could affect your son's health, it's important that he know about your medical history. You do not have to meet with him to give him the information. Ask your surgeon to write a letter to your son which covers the family medical history.

Your son will probably be shocked to learn that his adoptive mother lied, but he may want to get in touch with you. Many adoptees feel the need to meet their birth parents in order to feel "complete." Experts have told me that the vast majority of birth parents and children who have been reunited were gratified with the outcome.

DEAR ABBY: You printed a letter from a woman asking questions about her grandchild traveling unattended on an airplane to visit her.

You might be interested to know that the American Automobile Association has prepared a brochure addressing this situation. It's titled "Flying Alone: Handy Advice for Kids Traveling Solo." Parents interested in obtaining a free copy of the informative brochure should send a long, business-sized (No. 10), self-addressed, stamped envelope to: AAA, Flying Alone -- MS75, 1000 AAA Drive, Heathrow, Fla. 32746. -- JERRY CHESKE, DIRECTOR, PUBLIC RELATIONS, AAA NATIONAL OFFICE, HEATHROW, FLA.

DEAR MR. CHESKE: I think the little booklet is a dandy for any parent who is contemplating sending an unaccompanied child anywhere by air. It gives helpful tips about what to expect at the airport, lists the various age restrictions for unaccompanied minors, and offers suggestions concerning what to say and do prior to the child boarding the plane. Thanks for letting my readers know it's available. And the price is right -- it's free!

DEAR ABBY: I am 30 and engaged to a 28-year-old woman I'll call Sharon. Her best friend, "Janie," asks very personal questions, like "How often do you two have sex?"

Sharon will lie to her and reply "Twice a month." I'm not there when Janie asks these questions, but I hear about it afterward from Sharon. I resent the questions and prefer that Sharon ignore her and pretend she didn't hear the question.

Sharon reasons that if she tells her friend a lie and the woman knows it's a lie, it will keep her guessing. I feel it is none of her business and doesn't deserve a response. How do you think this should be handled? -- BOB IN NEW HAMPSHIRE

DEAR BOB: Ask Sharon, "What's wrong with telling your friend that you do not care to respond to such personal questions?"

For everything you need to know about wedding planning, order "How to Have a Lovely Wedding." Send a business-sized, self-addressed envelope, plus check or money order for $3.95 ($4.50 in Canada) to: Dear Abby, Wedding Booklet, P.O. Box 447, Mount Morris, Ill. 61054-0447. (Postage is included.)

DEAR ABBY: My 3-year-old son recently threw a tantrum in a large department store. I had called a "time-out," and he started yelling and screaming.

I picked him up and started for the car. All the while, he cried and struggled to get away from me. At one point, I put him down to get a better hold on him. He threw himself on the floor and lay flat. It's not easy to pick up a heavy child who won't cooperate, but I managed, then took him to the car to finish his time-out.

After the episode was over, it struck me that not one person questioned whether this child, who was trying so desperately to get away from me, was mine! How did they know whether he was throwing a tantrum or if, perhaps, I was kidnapping him?

Although I'm grateful no one tried to interfere, I'm also alarmed that they didn't.

Did I do the right thing when my son threw that tantrum, Abby? Or was there a better way to handle this? I'm a young mother, and if there's a better way, I'd like to know. -- CARING PARENT IN ARIZONA

DEAR CARING: Under the circumstances, you handled the situation appropriately, and I agree, it is alarming that the public accepts without question a child being forcibly carried from a public place.

Although it is unlikely a kidnapper would want to draw attention by forcing a screaming child out the door of a department store, if customers observe a suspicious situation, store clerks or management should be notified immediately. Most stores have policies to deal with such incidents. Should police intervention be necessary, management would be able to initiate security procedures and could reach emergency services faster than customers.

The National Committee to Prevent Child Abuse shared the following tips for parents, which you and others might find useful. Read on:

HOW TO HAVE A HAPPY SHOPPING EXPERIENCE WITH CHILDREN

1. Establish "rules for shopping" before leaving home. If you have a "no candy" rule, be clear and consistent about it. Review the rules periodically so they are familiar to even small children.

2. Take along a favorite toy or book, or a surprise treat to eat during the shopping trip.

3. Make up "store" games that engage the child. A suggestion: As you select fruits and vegetables or canned foods at the market, ask the child, "What could we make from oranges?" "What could we make from apples?"

4. Let the children know ahead of time that good behavior while shopping will earn them a treat later in the day.

5. Try not to let a shopping trip interfere with the children's naps or mealtimes. Plan your outing when children are well rested and not hungry.

6. Reinforce good behavior. Let your child know you appreciate his or her willingness to cooperate.

7. If the child misbehaves, remove him or her to a more private place to discuss the behavior. Avoiding a public scene will make you (and the child) feel better.

For everything you need to know about wedding planning, order "How to Have a Lovely Wedding." Send a business-sized, self-addressed envelope, plus check or money order for $3.95 ($4.50 in Canada) to: Dear Abby, Wedding Booklet, P.O. Box 447, Mount Morris, Ill. 61054-0447. (Postage is included.)

DEAR ABBY: I am a committed recycler. If I have a choice between two similar products, I'll choose the one that has the least packaging and/or is the most recyclable. When I buy fruit and vegetables, I do not put each item into its plastic bag. I bring my own cloth bags for my groceries. I wash my fruits and vegetables when I get home, so I don't mind if they are handled a couple more times along the way.

My problems begin when I reach the checkout counter. First, I hear a big sigh. Then they try to put all my produce into separate plastic bags. Sometimes the bagger even lines my cloth bag with a plastic one. What's the point in bringing my own bags if I take home as much plastic as if I hadn't brought them?

On occasion, I have even tried to bag my own groceries, but the employees just roll their eyes, or glare at me.

Abby, please remind checkout personnel that customers who bring their own bags are trying to conserve our resources and are concerned about our environment. -- TEXAS RECYCLER

DEAR RECYCLER: The next time you're in a checkout line and the bagger asks, "Paper or plastic?" say, "Neither, thank you. I brought cloth bags, so it's not necessary to segregate the produce."

DEAR ABBY: Re the judge and Ph.D. who were planning their wedding and wanted to know how they should be properly announced at the ceremony:

In my opinion, your advice was off the mark. In this day and age of women keeping their own names and having their own titles, announcing them as "Mr. and Mrs. Hisfirstname Hislastname" is inappropriate. This portion of the ceremony is about the new status of the couple AND their "new names."

While it's true that the wedding is "about the two of you becoming husband and wife, not judge and doctor," it is also true that becoming husband and wife is NOT about the wife's being called Mrs. Hisfirstname Hislastname anymore. Or even about the titles of "Mr." or "Mrs." where those are not applicable.

How about omitting this outdated "announcement" of new names and identities altogether? Is there any reason the presentation cannot be along the lines of, "Let's welcome John and Sally, husband and wife," or eliminated entirely? -- FLORIDA LAWYER

DEAR FLORIDA LAWYER: Of course not. Today, many couples opt for customizing their wedding ceremonies, and most clergy are cooperative about adding or deleting from the standard text.

That letter prompted some strong reactions from my readers. Read on for a letter with a very different viewpoint from yours:

DEAR ABBY: Dr. D., the Ph.D. from Arcadia, proves only that some educated and intelligent people are not necessarily smart. She may have a doctorate in education, but she failed Common Sense 101.

If I were the judge who is marrying her, I'd put a "stay of execution" on this wedding ceremony. In fact, I'd run as far as I could away from this "doctor" -- maybe to another state or country.

If I seem to be hard on this woman, it's because I've seen, met, spoken to, and even broken bread with this type of person. These people are selfish and self-centered. It's unfortunate that they don't recognize themselves. By the way, I'm an M.D., but you can call me "Bill." -- A BIG FAN IN SANTA CLARITA, CALIF.

To order "How to Write Letters for All Occasions," send a business-sized, self-addressed envelope, plus check or money order for $3.95 ($4.50 in Canada) to: Dear Abby, Letter Booklet, P.O. Box 447, Mount Morris, Ill. 61054-0447. (Postage is included.)