Although many people have no symptoms by the time they are diagnosed with MEN2A
, usually through the discovery of medullary thyroid cancer, symptoms related to the syndrome can include high blood pressure, diarrhea, skin lesions, heavy sweating, constipation, glucose intolerance, loss of bone density, memory problems, depression, severe fatigue or gastroesophageal reflux.
In MEN2B the 918 mutation alters the substrate specificity of RET tyrosine kinase and induces a different set of signalling pathways to those in MEN2A. Y1062 (a critical regulator of Ret9 signalling) appears to be an important location on the gene.
RET activation by germline MEN2A and MEN2B mutations.
Hirschsprung disease in MEN2A: increased spectrum of RET exon 10 genotypes and strong genotype-phenotype correlation.
Among the 192 MTC patients with available clinical information, 146 patients had sporadic MTC, 15 patients MEN2A, 14 patients FMTC, and one subject had MEN2B.
MTC: Medullary thyroid carcinoma, MEN2A: multiple endocrine neoplasia type 2 A Total: 191 patients Sporadic MTC n: 146 (76.5%) Familial MTC n: 14 (7.3%) MEN 2A n: 15 (7.9%) Mutation carriers from known families n: 16 (8.4%) Note: Table made from pie chart.
Preoperative CT level was significantly higher in sporadic cases compared with the MEN2A and FMTCs (p<0.05) (Table 4).