GH1 and short stature due to growth hormone qualitative anomaly: In many familial cases, there are defects in, or deletions of, the gene coding for GH (GH1) or the GH-releasing hormone receptor (GHRHR), which lead to either classical GH deficiency or GH that is biologically inactive (9, 10); in cases where GH is inactive, as in Kowarski syndrome, the apparent serum concentration of GH may be normal or even slightly elevated (11).