The increase in some of those is linked to inborn errors of metabolism, such as N-acetylalanine and 3-methylglutaric acid, which correspond to aminoacylase I deficiency [63] and 3-hydroxy-3-methylglutaryl CoA lyase deficiency [64], respectively. This evidence concerns the gene HMGCL and hyperinsulinemic hypoglycemia, familial, 4.