Growth Hormone Binding Protein

Reduced or absent GHBP is found in GH insensitivity due to inactivating receptor binding mutations as typified by Laron dwarfism. The most clinically relevant use of GHBP measurements is to confirm suspected Laron dwarf GH insensitivity due to genetic GH receptor defect. Other forms of GH receptor insensitivity, however may have normal or high GHBP levels. The levels of GHBP may be explained by the underlying mechanism for insensitivity, accordingly, inability to dimerize, errors in the trans-membrane structure, or in downstream actions may have high or normal GHBP levels.

Studies show that GHBP levels decrease in acromegaly, with normalization on successful treatment. The converse is not true – high GHBP levels are not found associated with GH deficiency.