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SDH Cascade Testing — SCE Medical Oncology MCQ

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HardCancer GeneticsSDH Cascade TestingSCE Medical Oncology

Predictive testing identifies a familial pathogenic SDHB variant in an asymptomatic 12-year-old. Which surveillance package most closely follows current UK genomic guidance?

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: C — Annual biochemistry now; abdominal MRI every 12–24 months and neck/thorax MRI every 2–3 years

Explanation lettering: D = shown as A · E = shown as C · C = shown as D · A = shown as E

E is correct. SDHB is the paediatric SDHx genotype for which surveillance starts earliest: annual clinical review and biochemistry from five years, abdominal MRI from ten and neck/thorax imaging from roughly 10–14, repeated at the stated intervals if normal. Biochemistry cannot exclude non-secretory head-and-neck disease, and MRI is preferred to repeated ionising-radiation imaging. Ultrasound alone is anatomically incomplete, and a normal baseline study does not remove age-related penetrance. Cascade testing is therefore valuable because a carrier enters a gene-specific longitudinal pathway rather than receiving a one-off scan.

Reference: NHS Genomics Education inherited PPGL guidance: https://www.genomicseducation.hee.nhs.uk/genotes/knowledge-hub/inherited-phaeochromocytoma-and-paraganglioma/