ATA Guidelines Tools

2 Diagnosis Î Other than for academic reasons or physician preference, it is not standard practice to analyze tumors of patients with sporadic MTC for somatic HRAS, KRAS or NRAS mutations or RET M918T mutations. (C) Î In very rare families who meet the clinical criteria for MEN2A or 2B, despite negative sequencing of the entire RET coding region, the relatives at-risk should be periodically screened by conventional methods for MTC, PHEO, and HPTH. After the initial evaluation, screening should continue at 1-3 year intervals. (C) Î Regarding hereditary MTC, the duty to warn a competent and capacitated patient or surrogate decision maker of the risk that an inherited RET mutation may pose to family members is standard of care. • This warning is ideally fulfilled in the setting of genetic counseling and should include a request for the patient to participate in identifying "at-risk" relatives. The "duty to warn" discussion should be a part of the informed consent process, where there is full disclosure of the seriousness of the disease and available forms of prevention and treatment. When a patient refuses to notify relatives or legal dependents of their risks, the physician should consider whether he has an ethical duty or obligation to warn family members at risk. He should consult a certified clinical ethicist either at his medical center, or another medical facility, or contact the American Thyroid Association Ethics Committee for guidance. (A) Î In pediatric patients who have not reached the age of consent it may be necessary for physicians to seek state intervention to prevent harm when there is parental refusal to inform their children of the risk for developing a malignant tumor. Practitioners with pediatric populations should consult published documents for guidance. (A) Î The duty to warn of genetic risk extends to both preconception and prenatal contexts. • Genetic counseling about the options of pre-implantation or prenatal diagnostic testing should be considered for all RET mutation carriers of childbearing age, particularly those with MEN2B. Parents who wish not to have prenatal RET mutation testing should be offered genetic counseling and informed of the availability of genetic testing of their child to detect a mutated RET allele. This is particularly important for mutations associated with the onset of MTC before 5 years of age. (A) Î Clinicians should be aware that falsely high or low serum calcitonin (Ctn) levels might occur with a variety of clinical diseases other than MTC and consider this possibility when serum Ctn levels are disproportionate to the expected clinical findings. (C) Î In interpreting serum Ctn data clinicians should be aware that Ctn levels are markedly elevated in children <3 years of age, especially <6 months of age. Also, Ctn levels are higher in males compared to females. (B)

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