Academy of Medical Sciences of I.R. Iran Archives of Iranian Medicine 1029-2977 27 8 2024 08 01 Pheochromocytoma/Paraganglioma Syndrome Type 1 Presenting with Atypical Symptoms and a Novel Pathogenic Variant in the SDHD Gene: A Case Report 447 451 10.34172/aim.28810 EN Elham Zohrehvand https://orcid.org/0009-0002-2096-5224 Nastaran Injinari Maryam Kiani Feyzabadi Kazem Aghili Farahnaz Ghaemi Reyhaneh Azizi https://orcid.org/0000-0002-0996-045X Journal Article 10.34172/aim.28810 2024 01 08 2024 04 22 This case report presents a 10-year-old patient diagnosed with pheochromocytoma/paraganglioma syndrome type 1 (PPGL1), underlined by a novel heterozygous pathogenic variant (c.154_161del, p.ser52Profster14) in the SDHD gene. Initially, the patient manifested symptoms unusual for pheochromocytoma, including polyuria and polydipsia; however, further diagnostic investigations revealed a pheochromocytoma (PCC) tumor in the adrenal gland. Subsequently, whole exome sequencing (WES) test identified a pathogenic frameshift variant in the SDHD gene, strongly suggestive of PPGL1. This study highlights the importance of considering atypical symptoms in diagnosing rare pediatric pheochromocytoma/paraganglioma tumors and underscores the value of genetic testing in identifying underlying genetic causes, thereby facilitating personalized management of the condition.