Cases of Borderline <i>In Vitro</i> Constitutive Thyrotropin Receptor Activity: How to Decide Whether a Thyrotropin Receptor Mutation Is Constitutively Active or Not?

Abstract

Our findings indicate that current methods to precisely classify mutants with only a slight increase of the basal activity as constitutively active are limited. The results concerning the level of the basal activity can be influenced by the vector and/or the cell system. A comprehensive clinical characterization of the respective patients appears as a necessary and promising adjunct for the activity classification of these borderline mutations.