Taking the case of Cit-1 as an example, the very early detection of the homozygosity of the common pathogenic variant c.852_855del in the SLC25A13 gene would translate to a near-100% probability of citrin deficiency in the NBS subject, allowing the treating physician to confidentially initiate immediate dietary intervention in the early neonatal period without the need to wait for further investigation, potentially saving the patient from catastrophic liver complications [17]. This evidence concerns the gene COPG2IT1 and hyperinsulinemic hypoglycemia, familial, 4.