G6PC1 and hepatocellular carcinoma: By contrast, patients with GSDIa with compound heterozygosity, for c.508C>T (p.Arg170X) and c.575C>T (p.Ala192Val), homozygosity for c.1039C>T (p.Gln347X), and compound heterozygosity for c.648G>T (p.Leu216Leu) and c.986A>T (p.Lys329Met), resulting in reduced G6Pase activity in vitro, have presented clinically with hepatocellular carcinoma, HCA, or acute pancreatitis, respectively.[35], [36], [37] Similarly, patients homozygous for the common Japanese c.648G>T (p.Leu216Leu) G6PC1 pathogenic splice variant are at increased risk of hepatocellular carcinoma.30