TPO and Pendred syndrome: Those were in 40.9% MEN2A, RET codon 634 mutation (9), in 18.2% Pendred syndrome (4), in 18.2% PTEN hamartoma tumor syndrome, in 9.1% (2) TPO gene mutation (hormone synthesis deficiency), in 9.1% MEN2, codon 804 mutation (2) and in 4.5% (1) DICER1 mutation.