FUT2 non-secretor status is associated with Type 1 diabetes susceptibility in Japanese children.

AIM: To examine the contribution of the FUT2 gene and ABO blood type to the development of Type 1 diabetes in Japanese children. METHODS: We analysed FUT2 variants and ABO genotypes in a total of 531 Japanese children diagnosed with Type 1 diabetes and 448 control subjects. The possible association of FUT2 variants and ABO genotypes with the onset of Type 1 diabetes was statistically examined. RESULTS: The se2 genotype (c.385A>T) of the FUT2 gene was found to confer susceptibility to Type 1A diabetes in a recessive effects model [odds ratio for se2/se2, 1.68 (95% CI 1.20-2.35); corrected P value = 0.0075]. CONCLUSIONS: The FUT2 gene contributed to the development of Type 1 diabetes in the present cohort of Japanese children.

Variants associated with autoimmune Type 1 diabetes in Japanese children: implications for age-specific effects of cis-regulatory haplotypes at 17q12-q21.

AIMS: The aim of this study was to clarify the significance of previously reported susceptibility variants in the development of autoimmune Type 1 diabetes in non-white children. Tested variants included rs2290400, which has been linked to Type 1 diabetes only in one study on white people. Haplotypes at 17q12-q21 encompassing rs2290400 are known to determine the susceptibility of early-onset asthma by affecting the expression of flanking genes. METHODS: We genotyped 63 variants in 428 Japanese people with childhood-onset autoimmune Type 1 diabetes and 457 individuals without diabetes. Possible association between variants and age at diabetes onset was examined using age-specific quantitative trait locus analysis and ordered-subset regression analysis. RESULTS: Ten variants, including rs2290400 in GSDMB, were more frequent among the people with Type 1 diabetes than those without diabetes. Of these, rs689 in INS and rs231775 in CTLA4 yielded particularly high odds ratios of 5.58 (corrected P value 0.001; 95% CI 2.15-14.47) and 1.64 (corrected P value 5.3 × 10-5 ; 95% CI 1.34-2.01), respectively. Age-specific effects on diabetes susceptibility were suggested for rs2290400; heterozygosity of the risk alleles was associated with relatively early onset of diabetes, and the allele was linked to the phenotype exclusively in the subgroup of age at onset ≤ 5.0 years. CONCLUSIONS: The results indicate that rs2290400 in GSDMB and polymorphisms in INS and CTLA4 are associated with the risk of Type 1 diabetes in Japanese children. Importantly, cis-regulatory haplotypes at 17q12-q21 encompassing rs2290400 probably determine the risk of autoimmune Type 1 diabetes predominantly in early childhood.

Parthenogenetic chimaerism/mosaicism with a Silver-Russell syndrome-like phenotype.

INTRODUCTION: We report a 34-year-old Japanese female with a Silver-Russell syndrome (SRS)-like phenotype and a mosaic Turner syndrome karyotype (45,X/46,XX). METHODS/RESULTS: Molecular studies including methylation analysis of 17 differentially methylated regions (DMRs) on the autosomes and the XIST-DMR on the X chromosome and genome-wide microsatellite analysis for 96 autosomal loci and 30 X chromosomal loci revealed that the 46,XX cell lineage was accompanied by maternal uniparental isodisomy for all chromosomes (upid(AC)mat), whereas the 45,X cell lineage was associated with biparentally derived autosomes and a maternally derived X chromosome. The frequency of the 46,XX upid(AC)mat cells was calculated as 84% in leukocytes, 56% in salivary cells, and 18% in buccal epithelial cells. DISCUSSION: The results imply that a parthenogenetic activation took place around the time of fertilisation of a sperm missing a sex chromosome, resulting in the generation of the upid(AC)mat 46,XX cell lineage by endoreplication of one blastomere containing a female pronucleus and the 45,X cell lineage by union of male and female pronuclei. It is likely that the extent of overall (epi)genetic aberrations exceeded the threshold level for the development of SRS phenotype, but not for the occurrence of other imprinting disorders or recessive Mendelian disorders.

Use of Gonadotropin-Releasing Hormone Analogs in Children: Update by an International Consortium.

This update, written by authors designated by multiple pediatric endocrinology societies (see List of Participating Societies) from around the globe, concisely addresses topics related to changes in GnRHa usage in children and adolescents over the last decade. Topics related to the use of GnRHa in precocious puberty include diagnostic criteria, globally available formulations, considerations of benefit of treatment, monitoring of therapy, adverse events, and long-term outcome data. Additional sections review use in transgender individuals and other pediatric endocrine related conditions. Although there have been many significant changes in GnRHa usage, there is a definite paucity of evidence-based publications to support them. Therefore, this paper is explicitly not intended to evaluate what is recommended in terms of the best use of GnRHa, based on evidence and expert opinion, but rather to describe how these drugs are used, irrespective of any qualitative evaluation. Thus, this paper should be considered a narrative review on GnRHa utilization in precocious puberty and other clinical situations. These changes are reviewed not only to point out deficiencies in the literature but also to stimulate future studies and publications in this area.

Molecular cloning of ovine and bovine growth hormone-releasing hormone receptors: the ovine receptor is C-terminally truncated.

To provide information about species differences in GH-releasing hormone (GHRH) receptors useful for studies of receptor-ligand binding properties and receptor function, we have cloned the ovine and bovine pituitary GHRH receptors (GHRHRs). The ovine receptor (oGHRHR) was cloned from a pituitary complementary DNA library and encodes a protein that is similar to that of porcine, human, rat, and mouse with, respectively, 84.3, 80.7, 75.9, and 74.0% amino acid identity. Surprisingly, oGHRHR has a 16 amino acid truncation at its carboxyl-terminal end when compared with GHRHRs from other known mammals. RT-PCR using pooled pituitary RNA from a different population of sheep could detect only truncated receptor. Bovine GHRHR (bGHRHR) was cloned by RT-PCR and shows 92.5% amino acid sequence identity with oGHRHR, but has no truncation. Genomic sequencing of the appropriate region of goat receptor intron 13 showed that the caprine receptor shares the same truncation seen in sheep. Photoaffinity cross-linking of GHRH to ovine and bovine pituitary membranes confirms that the native ovine pituitary GHRHR protein is smaller by the amount predicted by the cloned sequences. The truncation did not affect GHRH binding as oGHRHR, bGHRHR, human GHRHR, and human GHRHR, which was truncated by site-directed mutagenesis to match the oGHRHR, all showed comparable GHRH binding affinity when expressed in transfected cell lines. In contrast, the ovine and truncated human receptors demonstrated enhanced sensitivity for GHRH stimulation of cAMP (lowered ED(50)) relative to hGHRHR and bGHRHR. This suggests that this C-terminal domain acts to inhibit cAMP signaling possibly through a role in receptor down regulation.

Growth hormone-releasing factor (GRF) regulates expression of its own receptor.

Recent studies have demonstrated that passive immunization of neonatal rats to GRF inhibited their somatic growth through the suppression of GH secretion. In this study, we investigated the changes in pituitary GRF receptor (GRFR) expression in GRF antibody (GRF-ab) treated rats. Neonatal rats were treated from day 1 to day 10 after birth with every other day sc injection of 50 microliters of normal rabbit serum (groups I: control & III) or rabbit serum containing GRF-ab (groups II & IV). In addition, groups III & IV received twice daily injection of recombinant human GH (0.4 microgram/kg, sc). The rats were sacrificed on day 11 and pituitaries were removed. The pituitary weights in all treatment groups were decreased compared to the control group (I). Total pituitary RNA was extracted and GRFR mRNA levels were determined by RNase protection assay. Receptor RNA levels were quantitated and normalized to an internal standard, glyceraldehyde 3-phosphate dehydrogenase (GAPDH). The ratios of GRFR mRNA to GAPDH mRNA were significantly decreased to 49.6 +/- 4.9 (mean +/- SD), 73.0 +/- 8.7, 43.6 +/- 9.5% of control group I in the experimental groups II, III, and IV, respectively (P < 0.01). These data suggest that (1) suppression of GH secretion in GRF-ab treated animals was due, at least in part, to a decrease in GRFR expression, (2) GRF may be necessary for its own receptor expression, (3) exogenous administration of GH suppresses pituitary GRFR mRNA.

A novel specific bioassay for serum human growth hormone.

Human GH receptor (hGHR) was recently expressed on a Ba/F3 cell line, which is a mouse pro-B cell lymphoma that has been induced to become a cloned cell line (Ba/F3-hGHR). Using a Ba/F3-hGHR cell line, we have established a bioassay for serum hGH. hGH stimulated cell proliferation in a dose-dependent manner in concentrations ranging from 1 ng to 100 ng/mL. Cell proliferation was not influenced by other hormones or growth factors in the bioassay, with the exception of insulin-like growth factor I (IGF-I) and GH binding protein. Free IGF-I significantly stimulated the proliferation of Ba/F3-hGHR cells at concentrations over 25.85 ng/mL in this bioassay system, but serum IGF-I did not stimulate cell proliferation because the sensitivity of cell proliferation was insufficient for free IGF-I in serum. GH binding protein, however, did suppress cell proliferation at the highest concentration (100 ng/mL), but did not at the average concentration (20 ng/mL). Human serum stimulated cell proliferation, which was completely suppressed by anti-GH antibody. The GH bioactivity of serum samples from normal children and patients with non-GH deficient short stature correlated strongly with the serum hGH concentration determined by immunoradiometric assay (IRMA) (r = 0.967, r = 0.924, P < 0.0001, respectively). The ratio of bioactivity/IRMA was 1.01+/-0.26 in sera from normal children and 1.18+/-0.24 and 1.00+/-0.29 at basal values and peak values in GH stimulation tests, respectively, in sera from patients with non-GH deficient short stature. The bioactivity/IRMA ratio for the serum GH bioactivity of a patient who had biologically inactive GH caused by an amino acid substitution was 0.333+/-0.056 (mean +/- SD). In conclusion, we established a new sensitive bioassay for hGH that is specific for hGH somatogenic action and is useful for screening of patients with short stature caused by biologically inactive hGH.

Growth hormone (GH) secretory dynamics in a case of acromegalic gigantism associated with hyperprolactinemia: nonpulsatile secretion of GH may induce elevated insulin-like growth factor-I (IGF-I) and IGF-binding protein-3 levels.

We describe a case of pituitary gigantism with low levels of growth hormone (GH), elevated insulin-like growth factor-I (IGF-I), and IGF-binding protein-3 (IGF-BP-3). The patient had characteristic clinical features of gigantism and acromegaly. The basal serum GH levels ranged from 1.2-1.9 micrograms/L, which were considered to be within normal limits. Serum GH response to either insulin-induced hypoglycemia or GH-releasing hormone was blunted. Frequent blood samplings during daytime and at night showed nonpulsatile GH secretion. Serum prolactin, IGF-I and IGF-binding protein-3 levels were elevated. After unsuccessful surgery, bromocryptine treatment normalized serum prolactin without affecting serum GH and IGF-I levels. Combined administration of octreotide and bromocryptine reduced serum GH and IGF-I levels. GH bioactivity as measured by Nb2 cell proliferation assay was within reference range. In the present case, nonpulsatile GH secretion and enhanced tissue sensitivity to GH may induce hypersecretion of IGF-I and IGF-BP-3 and cause clinical acromegalic gigantism.

Demonstration of insulin-like growth factor I in human urine.

Immunoreactive and receptor-reactive insulin-like growth factor I (IGF-I) was demonstrated in human urine. Thirty percent of the IGF-I immunoreactivity in urine was free, and the remainder was a high mol wt form (approximately 43K). Urinary IGF-I was quantitated by RIA after extraction with octadecylsilyl silica cartridges (Sep-Pak C18 cartridge), a method that measures only free IGF-I. The mean urinary immunoreactive IGF-I levels in normal adults (n = 8) and patients with acromegaly (n = 10) or hypopituitarism (n = 9) were 72 +/- 7 (+/- SEM), 225 +/- 34, and 19 +/- 4 pg/mg creatinine, respectively; these mean values were significantly different from one another. The results indicate that IGF-I is present in human urine and that the quantity in urine is altered in patients with GH excess and deficiency.

A novel compound heterozygous mutation in the steroidogenic acute regulatory protein gene in a patient with congenital lipoid adrenal hyperplasia.

Congenital lipoid adrenal hyperplasia (CLAH) is an autosomal recessive disorder characterized by impaired synthesis of all adrenal and gonadal steroid hormones. Recently, it was reported that mutations in the steroidogenic acute regulatory protein (StAR) gene cause CLAH. In the present study, we have analyzed the StAR gene of a Japanese patient with CLAH. PCR amplification and subsequent nucleotide sequencing of the StAR gene and those of her parents revealed that the patient has a compound heterozygous mutation of this gene. In one allele, an undescribed G to C transversion in codon 217, which occurred at the last base of exon 5 and thus altered the splice donor site sequence, apparently resulted in a substitution of Arg to Thr (AGG to ACG: R217T), and in the other allele, a C to T transition in codon 218 caused a substitution of Ala to Val (GCG to GTG: A218V), which has been previously shown to abolish StAR activity. In vitro expression analysis of an allelic minigene that consists of exons 4-6 of the R217T mutant StAR gene showed that the G to C transversion in the splice donor site of exon 5 caused by the R217T mutation disrupts normal splicing, resulting in the complete skipping of exon 5, which alters the translation reading frame of exon 6, introduces a stop codon at amino acid position 174, and thus impairs the activity. A functional expression study of the R217T replacement mutant revealed that the mutant has no steroidogenesis-enhancing activity if the transcript of the R217T mutant allele is ever spliced normally and translated into the protein. From the genetic analysis of 50 healthy subjects, the novel R217T mutation was unlikely to be due to polymorphism. Together, these results indicate that this patient is a compound heterozygote for the mutation in the StAR gene (T217R and A218V) and that these mutations inactivate the StAR function and give rise to clinically manifest CLAH.

Urinary growth hormone (GH) measurements are useful for evaluating endogenous GH secretion.

Daily (24-h) urinary GH excretion was measured using a highly sensitive sandwich enzyme immunoassay in 10 normal adults, 6 patients with hypopituitarism, 25 normal but short children who had normal plasma GH responses (peak plasma GH level, greater than 10 micrograms/L) to provocative tests, and 8 patients with acromegaly. The mean urinary GH values in the normal adults, patients with acromegaly, and patients with hypopituitarism were 13.8 +/- 4.0 (+/- SE) and 431.1 +/- 149.1 ng/g creatinine (Cr) (1.56 +/- 0.45 and 48.77 +/- 16.87 ng/mmol Cr) and undetectable, respectively; these mean values were significantly different from each other. In the normal but short children the urinary values ranged from undetectable to 55.8 ng/g Cr (6.31 ng/mmol Cr). All of the normal but short children and 4 patients with hypopituitarism participated in a 24-h endogenous GH secretion study. The urinary GH values correlated significantly with the mean 24-h plasma GH concentrations as an index of endogenous GH secretion (r = 0.81; P less than 0.001) and plasma somatomedin-C levels (r = 0.67; P less than 0.001), respectively. In 6 patients with acromegaly whose plasma GH levels were constant throughout a 4-h period, the urinary GH values also significantly correlated with the mean plasma GH levels (r = 0.95; P less than 0.01). These data indicate that urinary GH measurements reflect endogenous GH secretion and that measurement of urinary GH excretion is a useful, simple, and practical method for evaluating endogenous GH secretion.

Turner syndrome and Xp deletions: clinical and molecular studies in 47 patients.

Although clinical features of Turner syndrome have primarily been explained by the dosage effects of SHOX (short stature homeobox-containing gene) and the putative lymphogenic gene together with chromosomal effects leading to nonspecific features, several matters remain to be determined, including modifying factors for the effects of SHOX haploinsufficiency, chromosomal location of the lymphogenic gene, and genetic factors for miscellaneous features such as multiple pigmented nevi. To clarify such unresolved issues, we examined clinical findings in 47 patients with molecularly defined Xp deletion chromosomes accompanied by the breakpoints on Xp21-22 (group 1; n = 19), those accompanied by the breakpoints on Xp11 (group 2; n = 16), i(Xq) or idic(X)(p11) chromosomes (group 3; n = 8), and interstitial Xp deletion chromosomes (group 4; n = 4). The deletion size of each patient was determined by fluorescence in situ hybridization and microsatellite analyses for 38 Xp loci including SHOX, which was deleted in groups 1-3 and preserved in group 4. The mean GH-untreated adult height was -2.2 SD in group 1 and -2.7 SD in group 2 (GH-untreated adult heights were scanty in group 3). The prevalence of spontaneous breast development in patients aged 12.8 yr or more (mean +/- 2 SD for B2 stage) was 11 of 11 in group 1, 7 of 12 in group 2, and 1 of 7 in group 3. The prevalence of wrist abnormality suggestive of Madelung deformity was 8 of 18 in group 1 and 2 of 23 in groups 2 and 3, and 9 of 18 in patients with spontaneous puberty and 1 of 23 in those without spontaneous puberty. The prevalence of short neck was 1 of 19 in group 1 and 7 of 24 in groups 2 and 3. Soft tissue and visceral anomalies were absent in group 1 preserving the region proximal to Duchenne muscular dystrophy and were often present in groups 2 and 3 missing the region distal to monoamine oxidase A (MAOA). Multiple pigmented nevi were observed in groups 1-3, with the prevalence of 0 of 7 in patients less than 10 yr of age and 15 of 36 in those 10 yr or older regardless of the presence or absence of spontaneous puberty. Turner phenotype was absent in group 4, including a fetus aborted at 21 wk gestation who preserved the region distal to MAOA. The results provide further support for the idea that clinical features in X chromosome aberrations are primarily explained by haploinsufficiency of SHOX and the lymphogenic gene and by the extent of chromosome imbalance in mitotic cells and pairing failure in meiotic cells. Furthermore, it is suggested that 1) expressivity of SHOX haploinsufficiency in the limb and faciocervical regions is primarily influenced by gonadal function status and the presence or absence of the lymphogenic gene, respectively; 2) the lymphogenic gene for soft tissue and visceral stigmata is located between Duchenne muscular dystrophy and MAOA; and 3) multiple pigmented nevi may primarily be ascribed to cooperation between a hitherto unknown genetic factor and an age-dependent factor other than gonadal E.

Comparison of the somatogenic action of 20 kDa- and 22 kDa-human growth hormones in spontaneous dwarf rats.

The somatogenic action of the 20 kilodalton human growth hormone (20 K) was studied using the spontaneous dwarf rat (SDR), which has an isolated GH deficiency. Saline or 2.5 microg, 10 microg, or 100 microg/rat/day of recombinant 20 K or 22 K was administered to prepubertal male and female SDRs for 10 days. Their body weights, serum IGF-I, glucose and insulin were measured, and their body composition was determined. Body weights and serum IGF-I increased dose-dependently in both the 20 K- and 22 K-treated groups. There was no significant difference in body weights and serum IGF-I between the 20 K- and 22 K-treated groups except at the dose of 100 microg/rat, in which the IGF-I concentrations were higher in the 22 K-treated male SDRs (P< 0.05: 20 K vs 22 K). Blood glucose was not significantly different between the Spague-Dawley (SD) normal rats and the SDR control groups; however, serum insulin levels of the SDR were higher than those of the SD control group (P< 0.05). Additionally, there was a tendency for serum insulin and glucose levels to increase following 22 K treatment, but the differences were not significant. The percentage of body fat decreased with hGH treatment in both groups (P< 0.01: GH 10, 100 microg/rat group vs SDR control group), however, no significant differences were observed in body composition between the 20 K and 22 K treatment groups. In summary, the 20 K-hGH showed almost the same somatogenic activity as the 22 K-hGH in prepubertal male and female SDRs.

Growth hormone and insulin-like growth factor I stimulate Leydig cell steroidogenesis.

Leydig cells from 40 days old rats were incubated with or without human growth hormone (hGH) or insulin-like growth factor I (IGF-I) in the presence or absence of human chorionic gonadotropin (hCG), and testosterone and cyclic AMP (cAMP) levels in the medium were measured. Neither hGH nor IGF-I increased testosterone production in the absence of hCG in concentrations up to 1000 and 100 ng/ml, respectively. However, both peptides increased hCG-induced testosterone production in a dose-dependent manner. The maximal stimulatory concentrations of hGH and IGF-I were 100 and 50 ng/ml, respectively. Human GH did not further enhance the IGF-I-stimulated steroidogenesis. The hGH-augmented steroidogenesis was inhibited by anti-hGH IgG and anti-IGF-I IgG. hGH also enhanced hCG-stimulated cAMP production time dependently, suggesting that the stimulatory effect of hGH on steroidogenesis was due to an increased cAMP production. These data suggest that the effect of hGH might be mediated by locally produced IGF-I, which may act as a modulator on gonadal development in the presence of gonadotropin.

Insulin-like growth factor I stimulates growth in normal growing rats.

The scarcity of purified somatomedin/insulin-like growth factor (SM/IGF) has prevented investigation of the mechanisms of SM/IGF action. Recently insulin-like growth factor I (IGF-I) has been synthesized by recombinant DNA technology. The availability of large quantities of the biosynthetic IGF-I made it possible to study its effects by administering 120 micrograms/day via s.c. implanted minipump to rats for 7 days. After this 7 day administration of IGF-I, the body weight increased to 197.6 +/- 3.5% of initial values; the value was significantly greater than that of the control (179.4 +/- 3.7% of initial values, P less than 0.01). The body length and tibial epiphyseal width in IGF-I-treated rats were also significantly increased over those of control rats. The weights of kidneys, liver, testes and pituitary in IGF-I-treated rats were greater than those in control rats as well. These results provide a first demonstration that IGF-I stimulates growth in normal rats in vivo, and suggest that IGF-I might be useful in the treatment of growth retardation.

Mechanized assay of serum cholinesterase by specific colorimetric detection of released acid.

An automated assay method has been developed for the measurement of serum cholinesterase activity. The samples were prepared by an automated liquid handling unit and incubated for 9.7 min at 30 degrees C, followed by automatic injection into a colorimetric flow injection determination system for acetic acid liberated from acetylcholine by cholinesterase catalytic activity. The coloration reaction employed is based upon the formation of 2-nitrophenylhydrazide utilizing a water-soluble carbodiimide and has a high selectivity for carboxylic acids. The coefficients of variation of the proposed method were 2.4% for within-run analysis (n = 14) and 2.6% for between-run analysis (n = 6). Sera of 55 hospitalized patients were analyzed and the values obtained correlated well with an automated differential pH method (gamma = 0.989).

GH and GnRH analog treatment in children who enter puberty at short stature.

It is well known that height at the onset of puberty is closely related to final height. To improve final height of short children who enter puberty at short stature, twenty-one short boys and six short girls were treated with a combination of GH and GnRH analog. The boys started the combination treatment at a mean age of 12.0 years when their mean height was 128.5 cm (-2.74 SD) and the girls at a mean age of 10.68 years when their mean height was 126.4 cm (-2.23 SD). The boys discontinued GnRH at a mean age of 16.88 years after a mean treatment period of 4.89 years when their height was 153.7 cm (-2.75 SD), and the girls at a mean age of 13.89 years after a mean treatment period of 3.20 years when their height was 143.3 cm (-1.94 SD). Bone age maturation significantly decelerated during the combination treatment. Bone age rarely exceeded 14 years in boys and did not exceed 13 years in girls. Bone age maturation during combination treatment decelerated after bone age 12 years in boys and 10.5 years in girls. On average, bone age matured at a mean rate of 0.48 years a year in boys and 0.56 years a year in girls during the combination treatment. During the combination treatment, height velocity did not decelerate rapidly and remained at 3-5 cm/year for a longer duration because of the bone age deceleration, although a definite pubertal growth spurt was not observed. As a consequence, the mean projected height SDS for bone age increased 1.50 (+/- 0.76) SD in boys and 1.24 (+/- 0.49) SD during the combination treatment. Although most of the patients have not yet reached their final height, combined GnRH analog and GH treatment should increase the pubertal height gain and the adult height in short children who enter puberty early for height, when the post-GST growth is taken into account. The combination treatment seems more effective in boys than in girls. This improvement is attributed to the lengthening of the treatment period by slower bone maturation and maintained growth velocity.

When and how to combine growth hormone with a luteinizing hormone-releasing hormone analogue.

The effect of combined treatment with growth hormone (GH) and a luteinizing hormone-releasing hormone (LHRH) analogue, or GH alone, on pubertal height gain was assessed in an uncontrolled study in 15 boys and 10 girls with GH deficiency (GHD). Seven boys and six girls were treated with GH alone (group 1), and eight boys and four girls were treated with a combination of GH and an LHRH analogue during puberty (group 2). Mean ages (+/- SD) at the start of GH treatment and at the onset of puberty were significantly lower in group 2 (8.0 +/- 3.3 years and 11.2 +/- 0.8 years, respectively, in boys, and 6.3 +/- 1.6 years and 10.8 +/- 0.7 years in girls) than in group 1 (12.8 +/- 1.9 years and 13.7 +/- 1.4 years in boys, and 11.2 +/- 1.0 years and 12.5 +/- 1.2 years in girls). Height at the onset of puberty was less in group 2 than in group 1, but the difference was significant only for the boys. Combination treatment was started at a mean age of 11.7 +/- 1.2 years in boys and 11.5 +/- 1.0 years in girls. The duration of the combination treatment was 5.1 +/- 1.5 years in boys and 2.3 +/- 0.7 years in girls. The duration of the period between the onset of puberty and the end of GH treatment was significantly longer in group 2 (6.8 +/- 1.2 years in boys and 5.5 +/- 1.0 years in girls) than in group 1 (4.3 +/- 1.6 years in boys and 3.6 +/- 1.4 years in girls). The pubertal height gain was also significantly greater in group 2 (36.7 +/- 6.5 cm in boys and 29.0 +/- 8.3 cm in girls) than in group 1 (21.9 +/- 4.1 cm in boys and 18.6 +/- 4.1 cm in girls). Final height was significantly greater in group 2 than in group 1 in boys. Although there was no significant difference in final height between groups in the girls, the change in height SDS from the start of GH treatment until final height was significantly greater in group 2 (2.7 +/- 1.6 in boys and 4.5 +/- 0.5 SD in girls) than in group 1 (1.0 +/- 0.8 in boys and 1.8 +/- 0.9 SD in girls), in both boys and girls. In conclusion, it appears that combination of an LHRH analogue and GH may increase the pubertal height gain and the final height of children with GHD. The improvement is attributed to the prolongation of the treatment period, permitting slow bone maturation, and to the maintenance of height velocity. This combination treatment appears to be more effective in boys than girls. To fully assess this therapeutic approach, prospective controlled studies are needed.