So, bowing to the greater expertise, here's an excerpt from an email from my mother explaining the situation. I have done some editing for clarity (and because I'm freakish perfectionist about mechanics; remember, I'm the non-medical guy in the family).
As most of you know already, there was some concern over a metabolic problem that was picked up on Diego's newborn screening. Long story short: Diego is okay. After much blood testing and many anxious moments and many tears, it has been determined that he has a "little" condition know as Duarte's Variant. The problem looked to be some type of Galactosemia and at first he was thought to have Galactokinase deficiency—a missing enzyme that converts Galactose. Colleen wouldn't have been able to continue breastfeeding and Diego would have been on a special diet all his life. The Duarte's variant is a minor level of the Galactokinase deficiency, but doesn't necessitate special treatment. This situation is known as an "Inborn error on Metabolism," meaning it is inherited. So Colleen and Armin both are carriers for some level of Galactosemia. They will now have go through some genetic testing to see what this may mean for future children. For the moment though, there is a great sense of relief and gratefulness. Since many of you are family, we will let you know how this plays out because it may have meaning in your own childrens' lives. At the very least, every expectant parent should know which tests are included in the newborn screenings in their own state—every state is different—and have the Galactosemia screening done for sure. It can make an enormous difference in a child's life.So, Diego isn't in danger of having the planet-eating alien creature Galactus attack him. Somebody found the Ultimate Nullifier and took care of that. But I will have to have a Galactus check before I have any children. Maybe a Darkseid check.