Disproportionate growth following long-term growth hormone treatment in short children with X-linked hypophosphataemia

Abstract

Three short prepubertal children with X-linked hypophosphataemia were treated with 1 IU recombinant human growth hormone (rhGH)/kg per week sc in addition to calcitriol and phosphate supplementation over a period of 3 years. Improvement of height standard deviation score (SDS) ranged from 1.0-1.7 SD based on an increase in sitting height of 1.5-2.9 SD, whereas subischial leg length improved only slightly by 0.3-0.9 SD. In all three patients, renal phosphate threshold concentration increased slightly and transient hyperparathyroidism was noted. Treatment of stunted children with X-linked hypophosphataemia is effective in improving growth velocity, but appears to aggravate the pre-existent disproportionate stature of such children.