The growth hormone receptor gene in the African pygmy.

Multiple studies indicate that the pygmy responds poorly to GH. A GH-binding protein, which is a fragment of the GHR is markedly diminished in pygmy serum, suggesting a defect in the GHR. Full analysis of the molecular nature and function of the GHR gene is incomplete, but with one enzyme BstNI restriction fragment length, polymorphism was noted in pygmies located in an intron. This was an uncommon finding in other non-pygmy populations. The alteration noted may be in linkage disequilibrium with an effective mutation responsible for changes in the GHR of the pygmy. This is most likely in the regulatory regions of either the 3' or 5' extensions.