DEAR ABBY: I'll bet "Jane in Long Island," who is 38 years old and is having a hard time adopting a child, wouldn't be told that she is too old to adopt an older, non-white or handicapped child. And she certainly is not too old to be a foster parent.

Every week, a local TV station runs a spot called "Waiting Child," seeking homes for hard-to-place children. There are literally thousands of these children sitting in orphanages, feeling unloved and unwanted because there is something "wrong" with them.Jane can moan about not being able to get pregnant, but it's really her shortsightedness that deprives her of the chance to open her heart and home to a truly needy child. Sign me . . . NO SYMPATHY IN CARMICHAEL, CALIF.

DEAR NO SYMPATHY: It takes a very special kind of person to open her heart and home to a "hard-to-place" child. God bless those who do.

DEAR ABBY: Well, here I go with my first letter to you. Something is bothering me, and I have to know the answer and I can't ask anyone else.

I have "A Positive" blood type, and my husband has "O Positive." Our child's blood type is "AB Positive."

The point is, I fooled around a little about the time I got pregnant. I need to know if this child could belong to my husband.

For obvious reasons I can't sign my name or have your reply come to our home, so please give me a fast "Confidential to Keeping My Fingers Crossed in Kentucky": affirmative, if the child could be my husband's; negative, if it couldn't be. Thank you. - K.M.F.C. IN KENTUCKY

DEAR K.M.F.C.: It's not that simple. According to Dr. Ronald S. Ostrowski, my genetic consultant at the University of North Carolina at Charlotte: "In all probability, the answer is `negative.' But there is a very small possibility that the husband has a `masked' gene. (This is called the `Bombay phenomenon.') For an absolutely foolproof test, tissue typing will provide an accurate answer."

Now uncross your fingers, and cross your heart you will never fool around again.

DEAR ABBY: You stated that the AIDS virus may lie dormant in the body for several years before symptoms of the disease appear.

Does that mean that one who has had a blood transfusion several years ago may be at risk from donor blood? Is not the blood of donors screened for antibodies? How much at risk is a person who has had a transfusion?

Thanks and best wishes. I enjoy your answers and learn from reading Dear Abby. - SCARED OF BLOOD TRANSFUSIONS

DEAR SCARED: According to a spokesperson for the American Red Cross, people who received blood transfusions between 1975 and 1985 should be tested for HIV, because BEFORE 1985, blood was NOT screened for the AIDS virus.

However, SINCE 1985, the blood supply has been closely screened and, according to the Centers of Disease Control, the chance of becoming infected with AIDS from a transfusion is now about 1 in 100,000. In order to eliminate even this tiny risk, many physicians advise their patients who are contemplating surgery to bank their OWN blood for use at that time.

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"How to Write Letters for All Occasions" provides sample letters of congratulations, thank-yous, condolences, resumes and business letters - even how to write a love letter! It also includes how to properly address clergymen, government officials, dignitaries, widows and others. To order, send your name and address plus check or money order for $2.89 ($3.39 in Canada) to: Abby's Letter Booklet, P.O. Box 447, Mount Morris, IL 61054. (Postage is included.)