Previous association studies have determined that a 9–15 bp indel locus in the premelanosome protein (PMEL) gene is responsible for a disease-causing mutation in feather color23, and dwarfism can be caused by a deletion mutation in the 3’ untranslated region (3’ UTR) of the growth hormone receptor (GHR) gene24. This evidence concerns the gene GHR and Severe short stature.