Summary of recommendations
| Report germline likely pathogenic/pathogenic variant in diagnostic setting | Surveillance* for affected proband | Offer predictive testing | Offer surveillance* if positive predictive test | |
| Individual with SDHA-associated tumour (wtGIST, paraganglioma, phaeochromocytoma), renal cancer, neuroblastoma and pituitary adenoma with immunohistochemical evidence of SDH deficiency, see table 1) | Yes | Yes Offer follow-up for initial tumour and surveillance for metachronous tumours (see recommendation 4) | Recommend for FDR, following detailed discussion | Offer surveillance (see recommendation 6) following detailed discussion regarding current knowledge and limitations |
| Individual with non-SDHA-associated tumour | Yes, recommend reporting is coupled with a recommendation that SDH IHC is performed and the finding is considered to be a non-actionable secondary finding unless there is immunohistochemical evidence of SDHB/SDHA loss in the tumour or a family history of SDHA-associated tumours† | No† | No† | N/A |
*Surveillance: annual symptom review, blood pressure monitoring, biochemistry with plasma metanephrines and 3–5 yearly imaging of neck, thorax, abdomen and pelvis, preferably with MRI from age 15.
†For individuals with non-SDHA-associated tumours identified to have a PGV in SDHA, we would consider these a non-clinically actionable finding, unless the tumour is demonstrated to show SDHB/SDHA loss or there is a family history of SDHA-associated tumours. If either IHC loss or family history is confirmed, then recommendations should shift to that for an individual with an SDHA-associated tumour.
FDR, first-degree relative; IHC, immunohistochemical; PGV, pathogenic germline variant; wtGIST, wild-type gastrointestinal stromal tumour.