“…There are many studies on the T4 and T3 kinetics in familial T B G deficiency. As for T4 kinetics, it has been reported that the half-time was shortened, the fractional turnover rate and distribution space were in-creased, but the extrathyroidal pool was reduced, the degradation rate being normal (Ingbar, 1961 ;Nikolai and Seal, 1967;Bayley et al, 1969;Shishiba et al, 1970;Suzuki et al, 1973;Sakurada et al, 1974). As to T3 kinetics, on the other hand, the longer half-time and decreased degradation rate were reported (Cavalieri et al, 1971;McConnon et al, 1972;Sakurada el al., 1974).…”