We report the case of a 7-year-old patient of short stature who had normal
GH secretion, but a very low serum IGF-I level. On admittance, his height a
nd weight were 102.2 cm (-3.8S.D.) and 15.7 kg (-1.8S.D)., respectively. Hi
s bone age was 2 years and 8 months. The serum GH responses to insulin, glu
cagon and L-dopa were all normal. GH secretion during sleep was also normal
, but the serum ICF-I level was very low (29 ng/ml). The serum IGF-I level
was greatly increased by the administration of GH. No mutation was detected
in the GH-1 gene. His height velocity was noticeably improved by GH treatm
ent.