Q: I'm black and my husband is Latino. We're expecting a baby boy. I'm wondering what's the likelihood of the baby having sickle-cell disease. Should we get genetic testing?

A: Genetic testing isn't really a factor here. To get a more accurate evaluation of your family's risk, ask your doctor to send some of your blood for a test called hemoglobin electrophoresis, which will indicate whether you carry the sickle gene. About 1 in 12 African-Americans and 1 in 18 Hispanic-Americans have the sickle-cell trait.

Sickle-cell disease is what's called an "autosomal recessive genetic disorder," meaning that two abnormal genes are needed for a baby to have sickle-cell disease. The disease occurs in about one in every 500 African-American births. So, there is roughly a 1 in 864 risk of a baby being born with sickle-cell disease toa couple like you two.

If you discover that you have one normal gene (A) and one sickle gene (S), have your partner tested. When each parent carries one normal gene and one sickle gene, every pregnancy has a 25% chance of a baby born with normal blood; a 25% chance of sickle-cell disease; and 50% chance of the baby being an unaffected carrier. If both of you have normal genes, you cannot have a child with sickle-cell diease.