Newborn screening test

Found out at 3 weeks old my daughters nb screening test showed elevated thyroid. Had it repeated. Results came back today that shows negative for thyroid but this time positive for a metabolic enzyme disorder called Valinemia. A very rare but very serious condition. So we had it repeated today at just over a month old. I've been an emotional wreck all day bc it could cause death. How accurate are these tests? Taken 3 times now. Also if your child has this rare disorder how is it going?? Dr said she'd just need a special formula & all would be ok, but Google says otherwise. She looks healthy all of the prenatal tests were negative, came on her own at 40 wks. She's 10 lbs so gaining weight normally. I'm just so scared bc she's our little rainbow 😭😭