DUAL DEFICIENCY FOR GROWTH HORMONE AND INSULIN-LIKE GROWTH FACTOR-1.487

Abstract

Severe dwarfism is found in:1) GH gene deletion with low serum GH and IGF-1 levels; normal growth occurs with recombinant human growth hormone (rhGH) therapy. 2) GH insensitivity syndrome (Laron's dwarfism) with GH receptor gene mutation, high serum GH and low IGF-1 levels; no growth occurs with rhGH therapy. These two disorders coexist in a 19 mo.old male with a height:67cm(-5.19 SD*), weight:5.9 Kg(-4.67 SD); head circum:45.5 cm (-1.89 SD). Basal and peak serum GH levels in response to L-dopa and Clonidine were: 0.8, 0.5 and 0.4, 0.9 ng/ml respectively. Bone age was 12 mo.at chronological age of 25mo. Treatment with rhGH at 0.1 mg/Kg three days a week was started at age 31 mo. with a height SD of -5.39; after 34 mo. posttreatment the height SD was -5.52.No improvement in growth velocity occurred when rhGH was given to the patient for 4 months in our pediatric clinic. During rhGH treatment, serum IGF-1 levels range from 3.5 to 17 ng/ml., IGFBP-3 was 0.2 ng/ml, and GHBP was 17 ng/ml. The failure of serum GH concentration to increase in response to provocative tests suggests GH gene deletion; while the lack of growth velocity, low IGF-1, low IGFBP-3 and low GHBP during rhGH treatment suggest an abnormality of the GH receptor resulting from deletion or point mutation of the gene for the GH receptor. These data provide evidence of a coexistence of a deficiency for GH and IGF-1 and makes this case unique.