Since NP can be an early manifestation of MEN 2A
, in younger patients a blood test to check the level of calcitonin should be performed as a screening method for medullary thyroid carcinoma (6,7,18).
Based on a large study enrolling 323 MEN 2A patients, Quayle et al.
Therefore, the ATA recommends that pheochromocytoma screening (by plasma or 24-hour urine fractionated metanephrines) should begin by age 8 in carriers of RET mutations associated with MEN 2B and mutated RET codons 634 and 630 and by the age 20 years in carriers of other MEN 2A RET mutations.
For instance, the presence of hemangioblastomas (suggestive of von Hippel-Lindau) or medullary thyroid carcinoma along with pheochromocytoma (suggestive of MEN 2A) strongly implies mutations in VHL or RET gene, respectively [27, 29].
At present, no single-step method exists to carry out a molecular analysis of the hotspots related to MEN 2A and FMTC that can be applied to routine diagnosis.
Cys634 mutations in the RET proto-oncogene in Spanish families affected by MEN 2A. Hum Mutat 1998;S1: S72-3.
High prevalence of the C634Y mutation in the RET protooncogene in MEN 2A families in Spain.
We think it is useful in the screening of RET for the most common mutation in MEN 2A and especially to establish the carrier status in members of families with MEN 2A and FMTC already characterized as having the 634 mutation.
High prevalence of the C634Y mutation in the RET proto-oncogene in MEN 2A families in Spain.
All of the patients had inherited MTC (MEN 2A, MEN 2B, or FMTC) and had known genomic RET mutations previously analyzed by sequence analysis (by S.N.T.
4), exon 11 would be screened initially for mutations at an electrophoretic temperature of 10[degrees]C, given that 87% of the mutations associated with MEN 2A involve codon 634 in exon 11 .
Predictive testing for multiple endocrine neoplasia type 2A (MEN 2A) based on the detection of mutations in the RET protooncogene.