Severe hypertriglyceridemia is increasingly leading to referrals to endocrinology clinics. Patients commonly present with clinical manifestations such as recurrent abdominal pain, acute pancreatitis, and eruptive xanthomas. We report the case of a young male patient with over 30 recurrent episodes of acute pancreatitis and extremely elevated triglyceride levels. Genetic testing identified a heterozygous pathogenic mutation in the 1-acylglycerol-3-phosphate-o-acetyltransferase 2 (AGPAT2) gene. Further deletion/duplication analysis of the AGPAT2 gene was negative. The clinical presentation closely resembled type I hyperlipoproteinemia. Despite the typical presentation of type I hyperlipoproteinemia, the identification of a heterozygous AGPAT2 mutation suggests a potential novel genetic contributor to familial hypertriglyceridemia. This finding highlights the importance of genetic analysis in understanding atypical presentations of hyperlipoproteinemia and underscores the need to explore this mutation's inheritance patterns and pathophysiological implications. The heterozygous AGPAT2 mutation may represent a novel genetic factor in familial hypertriglyceridemia. Further research is needed to clarify its clinical significance and inheritance mechanisms.