Stature is a highly heritable trait controlled by only partially known genetic and environmental factors. Candidate mediators are growth hormone (GH), insulin-like growth factor-I (IGF-I), their respective receptors and binding proteins, and intracellular factors mediating signal transduction of these receptors. Pygmies exhibit an extreme form of non-disease related short stature, showing an endocrine profile similar to Caucasian individuals with idiopathic short stature (ISS). Since their growth has attracted the attention of the Western world, explorers and scientists have measured literally thousands of pygmies living throughout the tropical forests of central Africa. The study of these subjects may significantly improve the knowledge of the mechanisms regulating normal growth in humans. This review analyzes the existing knowledge on the GH/IGF-I axis and short stature of the Pygmy population. We illustrate in depth our recent genetic studies on the ethnic group of Pygmies called Babinga, living in the forest of Cameroon. First, we have excluded that the Pygmies’ growth could be affected by chronic inflammatory diseases, since they show a normal functioning immune system with a hyper-production of immunoglobulins from birth. Furthermore, our studies suggest that the size of Pygmy subjects is reduced from birth, compared to a neighbouring population, and that it is associated with reduced GH and GH receptor gene expression. These results provide a research target for future epistatic as well as epigenetic investigations.
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