Abstract
Prolidase deficiency (PD) is a rare autosomal recessive metabolic disorder caused by pathogenic variants in the PEPD gene, which is responsible for making prolidase and collagen resynthesize. It leads to a wide range of clinical symptoms, including skin ulcers, intellectual disability, and recurrent infections. Diagnostics are based on the presence of dipeptides in the urine and prolidase activity in various cells, as well as the detection of the pathogenic variant in the PEPD gene; however, no standard method is currently known for its diagnosis nor for its treatment. Case 1 presents a 17-year-old male with dyspnea, cyanosis, and pulmonary arteriovenous malformations (AVMs), an atypical presentation for PD. Case 2, a one-year-old female with fever, seizures, productive coughs, erythematous ulcers, and developmental delays, highlights the disease's broad symptoms. This study widens our understanding of PD, especially for lesser-known populations, such as the population in Iran. It indicates considering PD in the differential diagnosis of various diseases and also a global collaboration for managing PD. The study also recommends a standard approach to diagnosing PD and a personal management system due to its broad manifestations. In addition, it indicates the need to consider different ethnic and geographical groups in future PD studies to further enhance our understanding of this rare disease.