By Taylor, Isovaleric acidemia, United States, December 30, 2019
After a long labor and complicated c-section, our beautiful son Samuel was finally here! He was such a calm and alert newborn. I remember the nurses wheeling him into my recovery room, and he would just be staring with those beautiful dark eyes watching everything. On Samuels 3rd day of life outside the womb, and the morning after he was discharged from the hospital, we got a call from Natalie from Vanderbilt Children's Hospital. She told us our son had an abnormal newborn screening, and asked if we could see her today.
Looking back I can see that she wanted us to come as quickly as possible while also trying to keep me as calm as possible. I knew any of the diseases tested through newborn screening were all very serious, but I tried to keep it together as my parents drove me, my husband, and our brand new baby on a long 2 hour car ride to the hospital. We finally get to meet Natalee, my sons genetic specialist, as she explained that my son may have Isovaleric Acidemia, and he would need to have blood drawn and urine collected for a series of tests. My son was 6 weeks old when we finally received all of the results back and confirmed this diagnosis. We had a couple of hospital stays for hypoglycemia and hypothermia which prompted us to treat him as if he does have IVA as those are both symptoms of the disease. We later discovered that the hypoglycemia was from failed breastfeeding, but the hypothermic episode is still unknown as it occurred just days after the hypoglycemia.
Treatment for Samuels IVA is a special amino acid modified formula that does not contain the amino acid leucine, as that is what his body cannot properly break down. Ingesting to much leucine through food can cause build up of Isovaleric acid in the blood which can lead to permanent physical and speech impairment, seizures, coma, and death. He is on a low protein food diet, which mainly includes fruits, vegetables, and grains. Animal products, nuts, soy, and legumes are usually much to high in protein for Samuel. He is also on a levocarnitine supplement, as carnitine aids the body in breaking down leucine. Sometimes glycine in also recommended for IVA, but his levels are high enough on their own. Samuel is 18 months and consumes 12 grams of protein a day from food, which can actually surprisingly hard to get on those days where he doesn't care about food, but luckily for us he usually loves food. Another way for leucine levels to rise in people who have IVA is during times of illness, especially if they have vomiting, diarrhea, and fevers.
Any illness with one or more of those symptoms usually required a hospital stay on a dextrose IV and monitoring to be sure his levels stay within a normal range. Fasting and dehydration are other ways for his leucine levels to rise, so it's extremely important that he eats his food and gets plenty to drink, on top of drinking all/most of his special formula. If he were to refuse his formula for a day, that would also require a hospital stay. For this reason, many infants and toddlers with IVA have had to have a feeding tube at some point, but Samuel has not needed this. Having the perfect balance of protein to meet their growth needs, but not cause a metabolic crisis can be difficult. If you restrict to much it can cause low bone density, poor health, and poor growth, so it's just as important to not over restrict. IVA is thought to affect 1 in 250,000 people in the United States. My husband and I have a 25% chance of having another child with IVA though as we are both carriers. IVA is a serious but very treatable disease, but many are likely to live a mostly normal life with diagnosis before life threatening metabolic crisis. The newborn screening program is super important for that reason.