Ppgl Genetic Testing Indication

---
name: ppgl-genetic-testing-indication
description: Determines when to suggest genetic testing for PPGL and educates patients about hereditary PPGL prevalence and testing significance, recommending testing for all PPGL patients per international guidelines while informing about the 20-40% hereditary rate and implications for family screening. Triggers include: 'Newly diagnosed PPGL patient,' 'Discussing hereditary risk with PPGL patient,' 'Considering genetic testing for PPGL patient and family.'
---

# PPGL Genetic Testing Indication and Patient Education

## STEP 1 — Gather Information
Confirm PPGL diagnosis via biochemical (elevated fractionated metanephrines/catecholamines) and imaging; obtain detailed family history of PPGL, related syndromes (VHL, RET, SDHx, NF1), and personal history of multifocal/bilateral tumors, early onset, or metastatic disease.

## STEP 2 — Rule In / Rule Out
Is the patient diagnosed with PPGL? If yes, proceed to offer genetic testing; if no, do not indicate PPGL-specific genetic testing (consider other indications).

## STEP 3 — Classify or Stratify
All PPGL patients are candidates for genetic testing regardless of family history; however, prioritize counseling for those with SDHB-negative immunostaining, metastatic disease, young age (<45 years), bilateral/multifocal tumors, or known familial history.

## STEP 4 — Decide
Offer germline genetic testing (multigene panel) after pre-test counseling; discuss hereditary PPGL prevalence (20-40%), implications for prognosis, family screening, and potential surveillance; obtain informed consent and refer to genetic counseling.

## Clinical Guardrails / Mimics / Pitfalls
Do not order testing without genetic counseling; avoid interpreting variants of unknown significance as pathogenic; do not rely solely on family history to decide testing (hereditary PPGL can occur de novo); do not forget that testing is not covered by Japanese health insurance except for medullary thyroid carcinoma; do not neglect to inform patients about possible psychological and insurance implications.

## Concrete Clinical Example
A 38-year-old woman with newly diagnosed left adrenal pheochromocytoma (elevated plasma metanephrine) and no family history is counseled about the 20-40% chance of hereditary PPGL, offered germline SDHB/VHL/RET/SDHD testing, and advised that a positive result would guide surveillance for metastases and familial screening.

**Source:** Japan Endocrine Society Clinical Practice Guideline for the Diagnosis and Management of Pheochromocytoma and Paraganglioma 2025, Japan Endocrine Society, 2025, DOI:10.1507/endocrj.EJ25-0165