Examples resolved by WGS from the current study include deep intronic variants in ASS1 causing citrullinemia, deletion of a complete exon in ARG1 causing arginase deficiency, and uniparental disomy with homozygous pathogenic variants in PCCA and HADHA, causing propionic aciduria and LCHAD deficiency, respectively. The gene discussed is HADHA; the disease is arginase deficiency.