- An individual who meets clinical criteria for a diagnosis of Multiple Endocrine Neoplasia Type IIa (MEN2A) or Familial Medullary Thyroid Cancer (FMTC).
- An individual in whom a diagnosis of Multiple Endocrine Neoplasia Type IIb (MEN2B) is confirmed or suspected.
- An individual diagnosed with medullary thyroid cancer.
- Paraganglioma or phaeochromocytoma under certain circumstances.
- Where a known pathogenic mutation is identified in a relative.
Genetic testing is recommended for good clinical care of individuals who are suspected of having a heritable mutation in this gene.
Because early detection of at-risk individuals affects medical management, testing of asymptomatic children is recommended. This should occur as soon as possible after birth in MEN2B and before age 5 in MEN2Ar (depending on the mutation).