SARDH and hyper-beta-alaninemia: For newborn NB-10 with a suspected MS MS diagnosis of hyperalaninemia, we found no pathogenic variants associated with the causative pyruvate carboxylase deficiency gene PC. However, serendipitously, we identified compound heterozygous variants c.1738T > C (p.Y580H, non-conservative amino acid change) and c.2050A > G (p.S684G, non-conservative amino acid change) of uncertain significance in the SARDH gene (Fig. 3).