A 1-year-old female presents with severe short stature, with a length more than 4 standard deviations below the mean. Laboratory studies reveal high resting and stimulated growth hormone (GH) levels, but very low insulin-like growth factor 1 (IGF-1) levels. Genetic testing reveals a pathogenic variant in STAT5b. In addition to severe growth failure, which of the following is a characteristic feature of this specific post-receptor form of GH insensitivity?