First is a nonsense variant (rs76353203; category 3; c.109C>T; p.Arg19*) in APOC3, a gene involved in the regulation of blood triglyceride (TG) levels [57], where all carriers had their measured TG levels below the 20th percentile, consistent with a previous report of homozygous carriers having nearly 60% reduction in plasma TG level [47] (variants in this gene causes apolipoprotein C-III deficiency, MIM# 614028) (Additional file 2: Fig. S3a). This evidence concerns the gene APOC3 and hyperinsulinemic hypoglycemia, familial, 4.