# Pheochromocytoma/Paraganglioma Syndrome Type 1 Presenting with Atypical Symptoms and a Novel Pathogenic Variant in the SDHD Gene: A Case Report

## TL;DR

A 10-year-old patient with atypical symptoms was diagnosed with a rare tumor syndrome caused by a new mutation in the SDHD gene.

## Contribution

A novel pathogenic variant in the SDHD gene is identified in a pediatric case of PPGL1 with atypical symptoms.

## Key findings

- A novel heterozygous frameshift variant (c.154_161del, p.Ser52ProfsTer14) in the SDHD gene was identified.
- Atypical symptoms like polyuria and polydipsia were linked to a pheochromocytoma tumor in the adrenal gland.
- Genetic testing confirmed PPGL1 and emphasized its importance in diagnosing rare pediatric tumors.

## Abstract

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.