Pancreatitis Is an Emerging Rare Complication of Classic Homocystinuria: A Case Series and Literature Review.

Classic homocystinuria (HCU) is caused by a deficiency in cystathionine beta-synthase, leading to excessive accumulation of homocysteine and methionine in plasma and tissues. Clinical manifestations typically involve the eyes, skeleton, central nervous system, and vasculature. Thromboembolic events, such as stroke and deep vein thrombosis, are well-recognized complications. Here, we report four patients with poorly controlled HCU who developed acute pancreatitis (AP) with varying outcomes, along with 11 additional cases identified through a literature review. This study highlights AP as a potential complication in poorly controlled HCU, expanding the clinical spectrum of the disease and offering guidance on surveillance and appropriate acute management.