en Pediatric Pediatric Original Research Original Research Recombinant human growth hormone (hGH) was given for 6 months or longer to 68 patients with GH deficiency, 6 with Turner's syndrome and 5 with achondroplasia, during 1986-1994 in a prospective study. The total weekly administered dose of GH was 0.6 u/kg. By random sampling, 29 of 68 GH deficient patients (42.6%) received twice weekly (2 iw) intramuscular (im) injections, 17 (25%) received twice weekly subcutaneous (sc) injections and 22 received hGH 6 times per week (6 iw) sc during the first 6 months of therapy. In the GH deficient group the mean pretreatment height velocity was 4 ± 1.2 cm! yr (mean ±SD). The mean velocity during the first 6 months of treatment was 8.7 ± 2.3 cm/yr (p<0.0005), regardless of the frequency and type of GH administration. During the second 6 months and second year of treatment, the mean growth rates were 7.7 ± 2.2 and 6.7 ± 2.2 cm, respectively. The mean increase in height during the first 6 months of therapy for the 2 iw im group (7.7 ± 1.6 cm) compared with the 2 iw sc group (7.6 ± 2.1) did not exhibit any significant difference (0.8<p<0.9). The comparison of growth velocities after 6 months of therapy using 2 i w sc (7.6 ± 2.1) and 6 iw sc (10.1 ± 3.3 cm/yr) in patients with GH deficiency revealed a statistically significant difference (p<0.002). 6 patients with Turner's syndrome aged 4.5 to 15.3 years were also treated with hGH. The mean pretreatment height velocity of 3.6 ± 0.9 cm/yr increased to 6.3 ± 0.8 cm/yr during treatment. 5 patients with achondroplasia aged 3-9.6 years also received hGH for more than 6 months, and height velocity during GH therapy increased compared to that before GH therapy (5.4 ± 1.4 cm/yr vs. 4.7 ± 0.9 cm/yr). Growth hormone deficiency, Turner\'s syndrome, Achondroplasia 303 306 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-1-331&slc_lang=en&sid=1 Z KARAMIZADEH 20031947532846005002 20031947532846005002 Yes From the Department of Pediatrics, Shiraz University of Medical Sciences, Shiraz, Islamic Republic of Iran. GH AMIRHAKIMI 20031947532846005003 20031947532846005003 No