Insulin-like growth factor-I treatment in two children with growth hormone gene deletions.
Two unrelated Brazilian patients had homozygous 6.7 kb deletions in the GH-1 gene (girl and boy, 1.8 and 3.3 yr, heights -7.9 and -6.0 SDS, respectively). Desensitization using small amounts of exogenous GH (0.033 IU/kg body weight/week, divided into daily s.c. injections) was attempted, but anti-GH antibodies appeared. Replacement with usual doses of hGH induced only transient increase in growth. IGF-I therapy with increasing doses resulted in catch-up growth without side-effects. Growth velocity was 7.5 cm/yr in the first year and 8.4 cm/yr in the next 6 months in patient 1, and 6.7 cm/yr in the first year, 5.9 cm/yr in the second year and 7.9 cm/yr in the third year of IGF-I treatment in patient 2, when the daily dose of 240 micrograms/kg was divided into three injections. IGFBP-3 levels were low (0.55 and 0.40 mg/I) and did not increase after IGF-I treatment, suggesting that this GH effect is not mediated by IGF-I, and injected IGF-I had a rapid disappearance rate. We conclude that IGF-I promotes growth by endocrine mechanisms and constitutes an effective treatment for patients with GH insensitivity secondary to GH antibodies.
Unidade de Endocrinologia do Desenvolvimento, Hospital das Clinicas, University of São Paulo School of Medicine, Brazil.
I J
IJ
Arnhold
S B
SB
Oliveira
M G
MG
Osorio
B B
BB
Mendonca
D000906:Antibodies / Q000097:blood; D001827:Body Height; D001938:Brazil; D002675:Child, Preschool; D005260:Female; D017353:Gene Deletion; D006130:Growth Disorders / Q000188:drug therapy / Q000235:genetics; D020249:Hormone Replacement Therapy; D019382:Human Growth Hormone / Q000235:genetics* / Q000276:immunology / Q000627:therapeutic use; D006801:Humans; D007223:Infant; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male
D000906:Antibodies; D018972:Insulin-Like Growth Factor Binding Protein 3; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I