An extensive genetic workup, including trio whole-exome sequencing, was performed, which confirmed the diagnosis of LPL deficiency with the same homozygous variant as her sister and a homozygous variant of uncertain significance in the NAA25 gene, a gene involved in protein N-terminal acetylation, which is a candidate gene with a potential relationship with the patient’s disease phenotype; however, this requires further evaluation. The gene discussed is LPL; the disease is hyperinsulinemic hypoglycemia, familial, 4.