ALDH5A1 variants were considered pathogenic (P) or likely pathogenic (LP) if the nucleotide change (1) resulted in a premature termination codon (stop-gain), (2) occurred at a splice site (within +/- 0–2 bp from reported, canonical splice site), (3) resulted in a frameshifting effect on the amino acid sequence, (4) caused loss of initiation codon, or (5) was previously reported in a confirmed, clinically affected individual with SSADH deficiency. The gene discussed is ALDH5A1; the disease is hyperinsulinemic hypoglycemia, familial, 4.