Malignant testicular germ cell tumors in postpubertal individuals with androgen insensitivity: prevalence, pathology and relevance of single nucleotide polymorphism-based susceptibility profiling.

STUDY QUESTION: What is the prevalence of malignant testicular germ cell tumors (TGCT) and its precursors, (pre-) germ cell neoplasia in situ (GCNIS), in late teenagers and adults who have androgen insensitivity syndrome (AIS) and the impact of an individual's genetic susceptibility to development of TGCT? SUMMARY ANSWER: No GCNIS or TGCT was diagnosed, but pre-GCNIS was identified in 14 and 10% of complete and partial AIS patients, respectively, and was associated with a higher genetic susceptibility score (GSS), with special attention for KITLG (rs995030) and ATFZIP (rs2900333). WHAT IS KNOWN ALREADY: Many adult women with AIS decline prophylactic gonadectomy, while data regarding the incidence, pathophysiology and outcomes of TGCT in postpubertal individuals with AIS are lacking. The relevance of genetic factors, such as single nucleotide polymorphisms (SNPs), in predisposing AIS individuals to TGCT is unknown. STUDY DESIGN, SIZE, DURATION: This multicenter collaborative study on prophylactically removed gonadal tissue was conducted in a pathology lab specialized in germ cell tumor biology. PARTICIPANTS/MATERIALS, SETTING, METHODS: Material from 52 postpubertal individuals with molecularly confirmed AIS (97 gonadal samples) was included; the median age at surgery was 17.5 (14-54) years. Immunohistochemical studies and high-throughput profiling of 14 TGCT-associated SNPs were performed. The main outcome measures were the prevalence of pre-GCNIS, GCNIS and TGCT, and its correlation with a GSS, developed based on the results of recent genome-wide association studies. MAIN RESULTS AND ROLE OF CHANCE: The earliest recognizable change preceding GCNIS, referred to as pre-GCNIS, was present in 14% of individuals with complete and 10% of those with partial AIS at a median age of 16 years. No GCNIS or invasive TGCT were found. The median GSS was significantly greater for those with, compared to those without, pre-GCNIS (P = 0.01), with an overlap between groups. Our data suggest important roles for risk alleles G at KITLG (rs995030) and C at ATFZIP (rs2900333), among the 14 studied TGCT-associated SNPs. LARGE SCALE DATA: N/A. LIMITATIONS REASONS FOR CAUTION: A limited number of cases were included. WIDER IMPLICATIONS OF THE FINDINGS: Our data suggest that the prevalence of pre-GCNIS in individuals with AIS beyond puberty is around 15%. Genetic susceptibility likely contributes to pre-GCNIS development in AIS but factors related to malignant progression remain unclear. Although data in older patients remain scarce, malignant progression appears to be a rare event, although the natural history of the premalignant lesion remains unknown. Therefore, the practice of routine prophylactic gonadectomy in adults with AIS appears questionable and the patient's preference, after having been fully informed, should be decisive in this matter. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by research grants from the Research Foundation Flanders (FWO) (to M.C.), the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq G0D6713N) (to B.B.M. and M.C.) and the European Society for Pediatric Endocrinology (ESPE), granted by Novo Nordisk AB (to J.K.). There are no competing interests.

[Primary amenorrhea: constitutional delayed puberty or hormonal disturbance]. / Primaire amenorroe: constitutioneel vertraagde puberteit of hormonale stoornis.

Investigations were carried out in 2 women of 17 and 18 years with primary amenorrhea, normal external female genitalia and delayed secondary sexual characteristics, for the reasons for delayed puberty. The 17-year-old patient had reduced values of FSH, LH and oestradiol. This disturbance in the hypothalamo-hypophysary axis was caused by hydrocephalus. Menarche occurred following drainage of the fluid. The 18-year-old patient had raised values ofFSH and LH and a lowered oestradiol value. There was therefore a disfunction existing at ovarian level, which appeared to be caused by an XX-gonadal dysgenesis. The patient was treated with hormones which led to breast development and menarche taking place. The cause ofprimary amenorrhea can mainly be divided into three categories: constitutional delayed puberty, delayed puberty due to hypogonadotropic hypogonadism, or delayed puberty due to hypergonadotropic hypogonadism. A carefully taken medical history, together with determination of the serum levels of FSH and LH, is helpful in differentiating between these categories. Subsequently, structured clinical management must be performed in order to approach the differential diagnosis of each of these categories, which will then be followed by the final diagnosis.

Identification of an AR Mutation-Negative Class of Androgen Insensitivity by Determining Endogenous AR Activity.

CONTEXT: Only approximately 85% of patients with a clinical diagnosis complete androgen insensitivity syndrome and less than 30% with partial androgen insensitivity syndrome can be explained by inactivating mutations in the androgen receptor (AR) gene. OBJECTIVE: The objective of the study was to clarify this discrepancy by in vitro determination of AR transcriptional activity in individuals with disorders of sex development (DSD) and male controls. DESIGN: Quantification of DHT-dependent transcriptional induction of the AR target gene apolipoprotein D (APOD) in cultured genital fibroblasts (GFs) (APOD assay) and next-generation sequencing of the complete coding and noncoding AR locus. SETTING: The study was conducted at a university hospital endocrine research laboratory. PATIENTS: GFs from 169 individuals were studied encompassing control males (n = 68), molecular defined DSD other than androgen insensitivity syndrome (AIS; n = 18), AR mutation-positive AIS (n = 37), and previously undiagnosed DSD including patients with a clinical suspicion of AIS (n = 46). INTERVENTION(S): There were no interventions. MAIN OUTCOME MEASURE(S): DHT-dependent APOD expression in cultured GF and AR mutation status in 169 individuals was measured. RESULTS: The APOD assay clearly separated control individuals (healthy males and molecular defined DSD patients other than AIS) from genetically proven AIS (cutoff < 2.3-fold APOD-induction; 100% sensitivity, 93.3% specificity, P < .0001). Of 46 DSD individuals with no AR mutation, 17 (37%) fell below the cutoff, indicating disrupted androgen signaling. CONCLUSIONS: AR mutation-positive AIS can be reliably identified by the APOD assay. Its combination with next-generation sequencing of the AR locus uncovered an AR mutation-negative, new class of androgen resistance, which we propose to name AIS type II. Our data support the existence of cellular components outside the AR affecting androgen signaling during sexual differentiation with high clinical relevance.

Mutations in the C-terminal part of insulin-like growth factor (IGF)-binding protein-1 result in dimer formation and loss of IGF binding capacity.

In an attempt to define domains in insulin-like growth factor (IGF)-binding protein-1 (IGFBP-1) that are involved in IGF binding, we subjected the carboxyl end of the coding region of IGFBP-1 cDNA to mutagenesis. Mutant cDNAs were isolated, characterized by sequencing, and cloned in an expression vector under control of the simian virus-40 (SV40) early promoter. The constructs were transfected into COS-1 cells, and the mutant proteins, secreted into the culture medium, were analyzed for IGF binding by ligand blotting. The results obtained show that deletion of the C-terminal 20 amino acids or introduction of frame-shifts in this region resulted in loss of IGF binding and for some mutants in the formation of dimeric IGFBP-1 molecules. These dimers are probably formed when cysteine-226 (Cys-226) is missing, and its putative partner is able to form intermolecular disulfide bonds. Site-directed mutagenesis demonstrated that most of the introduced point mutations in the C-terminal region did not affect IGF binding. Only mutation of Cys-226 to tyrosine completely abolished IGF binding, as did the introduction of a negatively charged amino acid in the vicinity of this residue. Again, dimers were observed, supporting that Cys-226 is essential for the conformation of IGFBP-1. In addition, our data suggest that an IGF-binding domain may be located in the vicinity of the intramolecular disulfide bond formed by Cys-226 and its putative partner.

Gene expression of the six insulin-like growth factor binding proteins in the mouse conceptus during mid- and late gestation.

The insulin-like growth factor-binding proteins (IGFBPs) comprise at least six distinct species that may modulate the action of IGFs. IGFs are important regulators of fetal growth and differentiation. To define sites of IGFBP mRNA synthesis, we have used in situ hybridization techniques in mouse conceptuses of different gestational ages (11-18 days). Expression of mouse (m) IGFBP-1 was detected in mouse conceptuses after day 12 of gestation and was restricted to the liver. Transcripts for mIGFBP-2, -4, and -5 were detected in various tissues and were found in all stages tested. In contrast, expression of mIGFBP-3 and -6 could be only weakly detected in late gestational conceptuses. Comparison of the expression patterns of mIGFBP-2, -4, and -5, which were found widely distributed in mouse conceptuses, revealed that mIGFBP-2 was expressed in the mesoderm-derived part of the tongue (day 13.5), but mainly in the ectodermal layer. Transcripts for mIGFBP-4, however, were detected only in the mesodermal part, whereas expression of mIGFBP-5 was restricted to the ectodermal layer. A similar distribution pattern was observed in the lung (day 18). In general, expression of mIGFBP-2 and -5 was detected in the same cells, whereas mIGFBP-4 and -5 were expressed mainly in different cell types. These data suggest that the different mIGFBPs might play distinct roles in mouse embryonal and fetal life.

Generation of antisera to mouse insulin-like growth factor binding proteins (IGFBP)-1 to -6: comparison of IGFBP protein and messenger ribonucleic acid localization in the mouse embryo.

The insulin-like growth factor (IGF) system is an important regulator of fetal growth and differentiation. IGF bioavailability is modulated by IGF binding proteins (IGFBPs). We have generated six different antisera, directed to synthetic peptide fragments of mouse IGFBP-1 through -6. The specificity of the produced antisera was demonstrated by enzyme-linked immunosorbent assay, Western blotting, and by immunohistochemistry on sections of mouse embryos of 13.5 days post coitum. Specificity for the IGFBP-2 through -6 antisera also was confirmed immunohistochemically in liver and lung of corresponding gene deletion (knock-out) mutant mice and wild-type litter mates. Immunohistochemistry and messenger RNA (mRNA) in situ hybridization on sections of mouse embryos of 13.5 days post coitum revealed tissue-specific expression patterns for the six IGFBPs. The only site of IGFBP-1 protein and mRNA production was the liver. IGFBP-2, -4, and -5 protein and mRNA were detected in various organs and tissues. IGFBP-3 and -6 protein and mRNA levels were low. In several tissues, such as lung, liver, kidney, and tongue, more than one IGFBP (protein and mRNA) could be detected. Differences between mRNA and protein localization were extensive for IGFBP-3, -5, and -6, suggesting that these IGFBPs are secreted and transported. These results confirm the different spatial localization of the IGFBPs, on the mRNA and protein level. The overlapping mRNA and protein localization for IGFBP-2 and -4, on the other hand, may indicate that these IGFBPs also function in an auto- or paracrine manner.

Human insulin-like growth factor (IGF) binding protein-1 inhibits IGF-I-stimulated body growth but stimulates growth of the kidney in snell dwarf mice.

The actions of insulin-like growth factor-I (IGF-I) are modulated by IGF binding proteins (IGFBPs). The effects of IGFBP-1 in vivo are insufficiently known, with respect to inhibitory or stimulatory actions on IGF-induced growth of specific organs. Therefore, we studied the effects of IGFBP-1 on IGF-I-induced somatic and organ growth in pituitary-deficient Snell dwarf mice. Human GH, IGF-I, IGFBP-1, and a preequilibrated combination of equimolar amounts of IGF-I and IGFBP-1 were administered sc during 4 weeks. Treatment with IGF-I alone induced a significant increase in body length (108% of control) and weight (112%) as well as an increase in weight of the submandibular salivary glands (135%), kidneys (124%), femoral muscles (111%), testes (129%), and spleen (126%) compared with saline-treated controls. IGFBP-1 alone induced a significant increase in weight of the kidneys (152% of control). Coadministration of IGF-I with IGFBP-1 neutralized the stimulating effects of IGF-I on body length and weight as well as on the femoral muscles and testes. In contrast, the weights of the submandibular salivary glands (143%) were not significantly different from those of IGF-I-treated animals, whereas the weights of the kidneys (171%) and spleen (156%) were significantly increased compared with IGF-I-treated mice. The effect of IGFBP-1 plus IGF-I on kidney weight was not significantly greater than the effect of IGFBP-1 alone. Western ligand blotting showed induction of the IGFBP-3 doublet as well as IGFBPs with molecular masses of 24 kDa, most probably IGFBP-4, by human GH, IGF-I alone, and IGF-I in combination with IGFBP-1. Our data show that coadministration of IGFBP-1 inhibits IGF-I-induced body growth of GH-deficient mice but significantly stimulates the growth promoting effects of IGF-I on the kidneys and the spleen. These data warrant further investigation because differences in concentrations of IGFBP-1 occurring in vivo may influence IGF-I-induced anabolic processes.

Isolation of a somatomedin-binding protein from preterm amniotic fluid. Development of a radioimmunoassay.

Amniotic fluid binding protein (AFBP) is a heat and acid stable somatomedin (Sm)-binding protein with a mol wt of 35-40,000 and an isoelectric point of +/- 4.7. It is reactive in RRAs for Sm and inhibits Sm activity in Sm bioassays. AFBP was purified from midgestational human amniotic fluid (AF) using acid-ethanol extraction, Sephadex G-150 chromatography, high speed gel filtration chromatography, and disc gel-electrophoresis. Specific binding activity (microgram equivalents per mg protein) was quantitated by incubation with 125I-insulin-like growth factor II and dextran-coated charcoal separation. Protein recovery was less than 1%. AFBP antiserum was produced by immunizing rabbits with purified AFBP. The antiserum was cleared of human serum albumin antibodies by affinity chromatography. Immunoelectrophoresis of 20x concentrated preterm AF and fetal serum resulted in one precipitin line. AFBP was labeled by the chloramine-T method. The AFBP antiserum specifically bound +/- 35% of added 125I-AFBP at a final dilution of 1:5000. A double antibody RIA was developed. The AFBP level measured by RIA in midgestation AF (n = 30) was 148 +/- 18 (SEM) and in term AF (n = 12) 72 +/- 36 mu geq/ml. Insulin-like growth factor I/Sm-C values (determined by RIA) in the same samples were uniformly very low (less than 0.10 U/ml). When serum was chromatographed on Sephadex G-200 at pH 2.2, AFBP-RIA activity eluted in one peak corresponding to a mol wt of 35-40,000. Highest activity was found in fetal serum (gestational age +/- 20 weeks) and lowest in serum from adults. The development of the AFBP-RIA may contribute to further elucidation of the physiological importance of Sm and the Sm-binding proteins in pre- and postnatal growth.

Somatomedin-C/insulin-like growth factor I-binding proteins in human amniotic fluid and in fetal and postnatal blood: evidence of immunological homology.

By using the chemical cross-linking agent dis-succinimidyl suberate and [125I]somatomedin-C/insulin-like growth factor I (Sm-C/IGF-I) to affinity label Sm-binding proteins, we identified a 30,000- to 40,000-dalton (30-40K) [125I] Sm-C-binding protein complex in midterm amniotic fluid and cord blood. An antibody raised against a Sm-binding protein purified from midterm amniotic fluid recognized this labeled complex not only in amniotic fluid but also in fetal serum and term cord and several postnatal human plasmas, indicating that the 30-40K Sm-binding proteins in each are similar or identical. The binding proteins in amniotic fluid appear to possess binding sites specific for Sm-C, because under the conditions employed, unlabeled Sm-C was at least 10-fold more potent than IGF-II or multiplication-stimulating activity in competing with [125I]Sm-C for binding. Although [125I]GF-II could be cross-linked to similarly sized proteins, unlabeled Sm-C also competed for this binding better than either unlabeled IGF-II or MSA (at least 5-fold greater potency). These findings suggest that this amniotic fluid Sm-binding protein is primarily a carrier of Sm-C, but does not exclude the possibility that a binding site or a distinct binding protein exists which is specific for IGF-II but not amenable to cross-linking by the procedure used. Because unlabeled Sm-C was less potent in inhibiting the binding of [125I]Sm-C to amniotic fluid than to cord plasma proteins, the amniotic fluid binding protein is either more abundant or less avidly binds [125I]Sm-C than the cord plasma binding protein.

Immunoassay of a somatomedin-binding protein from human amniotic fluid: levels in fetal, neonatal, and adult sera.

We developed a specific RIA for a somatomedin (Sm)-binding protein, with an approximate mol wt of 35-40,000, purified from midgestational human amniotic fluid (AF) and termed AF-binding protein (AFBP). After Sephadex G-200 chromatography AFBP-RIA activity was found in fractions of fetal and cord serum only at a kav corresponding to a mol wt of +/- 40,000. Whole serum or plasma dilutions in a range of 1:20 to 1:600 showed parallelism with the standard curve. Sm-binding activity in fetal serum was found solely at a mol wt of 30-40,000; in cord serum additionally at a mol wt range of 150-200,000. AFBP serum or plasma concentrations determined by RIA were influenced by several factors: AFBP values in eight adults were highest in the morning (mean +/- SEM, 0.7 +/- 0.1 mu geq/ml) and lowest at night (0.3 +/- 0.1). AFBP values in pre- and postnatal serum showed a gradual decline with increasing age: fetal serum: mean +/- SEM, 36.7 +/- 15.7 (n = 17); adults: 0.6 +/- 0.07 mu geq/ml (n = 19). In serum from GH-deficient children AFBP concentrations were significantly higher than in an age-matched control group (P less than 0.05). Elevated values also were found in serum of children with end-stage renal failure and in serum of pregnant women at 36 weeks of gestation. AFBP was found in urine of preterm infants (mean +/- SEM, 0.04 +/- 0.005 mu geq/ml; n = 31). AFBP immunoreactivity was demonstrable in serum of three orangoutan mothers and their three children and in medium of a hepatoma cell line (PLC/PRF/5) but not in bovine, porcine, rabbit, or rat serum or in medium of cell cultures of (pre-)term placentae. We conclude that AFBP immunoreactivity is present in pre- and postnatal serum and has striking similarity to an unsaturated serum Sm-binding protein with a mol wt of +/- 40,000.

Hereditary defect in biosynthesis of aldosterone: aldosterone synthase deficiency 1964-1997.

We studied two of the three patients with a hereditary defect in the biosynthesis of aldosterone originally described by Visser and Cost in 1964. All three presented as newborns with salt-losing syndrome and failure to thrive. The original biochemical studies showed a defect in the 18-hydroxylation of corticosterone. According to the nomenclature proposed by Ulick, this defect would be termed corticosterone methyl oxidase deficiency type I. We measured plasma steroids in the untreated adult patients and performed molecular genetic studies. Aldosterone and 18-OH-corticosterone were decreased, whereas corticosterone and 11-deoxycorticosterone were elevated, thus confirming the diagnosis of corticosterone methyl oxidase deficiency type I. Cortisol and its precursors were in the normal range. Genetic defects in the gene CYP11B2 encoding aldosterone synthase (P450c11Aldo) have been described in a few cases. We identified a homozygous single base exchange (G to T) in codon 255 (GAG) causing a premature stop codon E255X (TAG). This mutation destroys a Aoc II restriction site. Digestion of a PCR fragment containing exon 4 of CYP11B2 (261 bp) with this restriction enzyme revealed in the two patients homozygous for the E255X mutation only a 261-bp fragment, whereas the heterozygous parents had three fragments (261 bp from the mutant allele and 194 and 67 bp from the wild-type allele). The mutant enzyme had lost the five terminal exons containing the heme binding site, and thus there was a loss of function enzyme. We conclude that the biochemical phenotype of these prismatic cases of congenital hypoaldosteronism can be explained by the patients genotype.

Double blind trial comparing the effects of two doses of growth hormone in prepubertal patients with chronic renal insufficiency.

Growth retardation is a major problem for children with chronic renal insufficiency (CRI). Recent studies have convincingly shown that recombinant human GH accelerates growth significantly, but the optimal GH dose with regard to long term growth response and safety has not yet been established. GH therapy was given to 23 prepubertal children (18 boys and 5 girls; mean +/- SD age, 7.1 +/- 3.6 yr; range, 1.6-14.1) with CRI and severe growth retardation in a double blind, dose-response trial. Patients were randomly assigned to either 2 or 4 IU GH/m2.day for 2.5 yr. During the first 6 months, there were comparable and significant increases in height velocity SD score for chronological age with both doses (P < 0.001). However, during the ensuing 2 yr, the higher GH dose induced a significantly greater improvement in height velocity SD score for chronological age than 2 IU GH. Catch-up growth was only sustained for 2.5 yr with 4 IU. In contrast, catch-up growth ceased after 6 months with 2 IU. Neither 2 nor 4 IU GH resulted in accelerated bone maturation during 2.5 yr of therapy. There was a significant increase in plasma insulin-like growth factor-I (IGF-I) levels with either dose, but significantly more so with 4 IU. Plasma IGF-II levels only increased significantly with 4 IU. The pretreatment elevation of IGF-binding protein-1 (IGFBP-1) levels decreased by 50% during the first study year with the higher GH dose, whereas there was no decrease with 2 IU. The elevated pretreatment IGFBP-3 levels increased comparably and significantly with either GH dose. Interestingly, only 4 IU resulted in a significantly greater increase in IGF-I than in IGFBP-3 levels. Regardless of GH dose, there was an insignificant decrease in fructosamine levels, whereas lipid and parathyroid concentrations remained constant. Renal function deterioration did not accelerate. GH therapy with 4 IU/m2.day induced and maintained catch-up growth during 2.5 yr in children with CRI without evidence of adverse effects. Bone maturation did not accelerate. This suggests that this higher GH dose may be beneficial for children with severe growth retardation secondary to CRI.

Hormonal evaluation of boys born with undescended testes during their first year of life.

We studied pituitary-gonadal function during the first year of life in 48 boys born with 56 undescended testes in order to test the hypotheses that functional insufficiency of the hypothalamo-pituitary-gonadal axis and disorders of testosterone (T) biosynthesis occur in such boys. Cryptorchidism persisted for longer than 1 yr in 29 boys (30 testes; group I), whereas spontaneous descent occurred in 19 boys (20 testes; group II), in 6 after the sixth month. A control group (group III) included 160 boys. Basal and peak LHRH-stimulated serum LH and FSH and basal serum T values were determined at 3, 6, and 12 months. Serum T, dihydrotestosterone (DHT), progesterone (P), 17-hydroxypregnenolone, 17-hydroxyprogesterone, dehydroepiandrosterone sulfate, and androstenedione before and after hCG administration were determined at age 1 yr. Comparing the 3 groups, cross-sectional evaluation revealed no significant differences in basal or peak LHRH-stimulated serum LH and FSH levels, except that basal serum LH levels were slightly higher in group II than in group III. Comparing groups I and II, longitudinal evaluation revealed similar basal and peak LHRH-stimulated serum LH and FSH values, with comparable changes with time. Basal serum T, DHT, and T precursor levels were similar in all three groups, with similar rises of T and DHT and variable minimal increases in androstenedione and dehydroepiandrosterone sulfate after hCG stimulation. We conclude that during the first year of life, boys with cryptorchidism have no functional insufficiency of the hypothalamo-pituitary-gonadal axis or disorders in T biosynthesis.

Dose-response study of biosynthetic human growth hormone (GH) in GH-deficient children: effects on auxological and biochemical parameters. Dutch Growth Hormone Working Group.

A multicenter dose-response study evaluated the effect of two different doses of biosynthetic GH on auxological and biochemical parameters in 38 prepubertal children with GH deficiency (GHD). Twenty-one were newly diagnosed, while 17 transfer patients had been on GH treatment for at least 1 yr before the study. New and transfer patients alike were treated with either 2 or 4 IU GH/m2.day sc. At evaluation all new patients had completed 1 yr of treatment, while transfers had completed 2 yr of treatment under study. In the new patients both doses resulted in a significant increase in height velocity (HV) and height SD score (SDS), with comparable bone maturation. After correction for the severity of GHD, the increase in HV SDS was significantly greater with 4 IU than with 2 IU (P less than 0.01). In the transfer patients HV, height SDS, and predicted adult height only increased significantly with 4 IU (P less than 0.05). Bone maturation was comparable for the two doses. There was a significant correlation between first year growth response and GH dose. In the new patients, the plasma insulin-like growth factor-I (IGF-I) concentration increased significantly without a significant difference between dosage groups. There was a positive correlation between growth response and increment of plasma IGF-I SDS. In new and transfer patients alike, above normal plasma IGF-I levels were observed, particularly with 4 IU. Hemoglobin-A1 remained constant with both GH doses in both groups, while cholesterol and LDL levels tended to decrease. In the new patients, the mean apolipoprotein-A1 level was lower than the control value after 1 yr on 4 IU GH. Treatment with 4 IU GH/m2.day led to a greater growth response than a dose of 2 IU in newly diagnosed as well as previously treated GHD patients. Bone maturation was comparable for both doses. No adverse effects were observed with the higher GH dose, but the long term effects on IGF-I and lipid metabolism need further attention.

Twenty-four-hour plasma growth hormone (GH) profiles, urinary GH excretion, and plasma insulin-like growth factor-I and -II levels in prepubertal children with chronic renal insufficiency and severe growth retardation.

We studied 24-h plasma GH profiles, maximal GH responses to arginine provocation and insulin-like growth factor-I (IGF-I) and IGF-II levels in plasma in 22 euthyroid prepubertal children (mean age, 9.5 yr) with chronic renal insufficiency (glomerular filtration rate, less than 20 mL/min.1.73 m2) and severe growth retardation [mean (+/- SD) height SD score (SDS), -2.8 (1.1)]. The 24-h GH profiles were analyzed using the Pulsar program. Girls had significantly higher 24-h GH secretion than boys (P less than 0.004). Children with end-stage nephrotic syndrome had higher baseline GH levels and total area under the curve (AUCo) than patients with dysplastic kidneys (P less than 0.05), while the area under the curve above baseline (AUCb) was similar in all types of renal diseases. The type of treatment (conservative, peritoneal, hemodialysis) did not significantly influence the 24-h GH secretion. No correlation was found between 24-h GH profiles and age, height SDS for chronological age, height velocity SDS for bone age, and weight for height. Fourteen children showed a normal 24-h GH profile, defined as a GH profile with well defined, regular GH peaks returning to baseline GH levels and a distinct day and night pattern (AUCb, 90-300 micrograms/L.24 h). Four children had low profiles, with GH peaks below 10 micrograms/L, returning to baseline GH levels and occurring almost exclusively during the night (AUCb, less than 90 micrograms/L.24 h). The remaining four children had elevated 24-h GH profiles, with GH peaks on top of elevated baseline GH levels of more than 3 micrograms/L (AUCb, 35-205 micrograms/L.24 h; AUCo greater than 300 micrograms/L.24 h). In all patients 24-h urinary GH and beta 2-globulin excretion was 100-1000 times higher than that in controls. The urinary GH excretion correlated significantly with all characteristics of the 24-h GH profiles (r = 0.57-0.59; P less than 0.05). The maximal GH response during the arginine tolerance test was normal in 66% of the children. The mean (+/- SD) SDS for bone age for the IGF-I plasma levels was +1.1 (1.9), and that for IGF-II was +3.6 (3.4). IGF-I levels correlated significantly with the AUCb, maximum GH, and GH peak characteristics of the 24-h GH profiles (r = 0.05-0.73; P less than 0.02-0.001). IGF-II levels did not show any correlation with the characteristics of the endogenous GH secretion.(ABSTRACT TRUNCATED AT 400 WORDS)

Phenotypic variation in a family with partial androgen insensitivity syndrome explained by differences in 5alpha dihydrotestosterone availability.

Mutations in the androgen receptor (AR) gene result in a wide range of phenotypes of the androgen insensitivity syndrome (AIS). Inter- and intrafamilial differences in the phenotypic expression of identical AR mutations are known, suggesting modifying factors in establishing the phenotype. Two 46,XY siblings with partial AIS sharing the same AR gene mutation, R846H, but showing very different phenotypes are studied. Their parents are first cousins. One sibling with grade 5 AIS was raised as a girl; the other sibling with grade 3 AIS was raised as a boy. In both siblings serum levels of hormones were measured; a sex hormone-binding globulin (SHBG) suppression test was completed; and mutation analysis of the AR gene, Scatchard, and SDS-PAGE analysis of the AR protein was performed. Furthermore, 5alpha-reductase 2 expression and activity in genital skin fibroblasts were investigated, and the 5alpha-reductase 2 gene was sequenced. The decrease in SHBG serum levels in a SHBG suppression test did not suggest differences in androgen sensitivity as the cause of the phenotypic variation. Also, androgen binding characteristics of the AR, AR expression levels, and the phosphorylation pattern of the AR on hormone binding were identical in both siblings. However, 5alpha-reductase 2 activity was normal in genital skin fibroblasts from the phenotypic male patient but undetectable in genital skin fibroblasts from the phenotypic female patient. The lack of 5alpha-reductase 2 activity was due to absent or reduced expression of 5alpha-reductase 2 in genital skin fibroblasts from the phenotypic female patient. Exon and flanking intron sequences of the 5alpha-reductase 2 gene showed no mutations in either sibling. Additional intragenic polymorphic marker analysis gave no evidence for different inherited alleles for the 5alpha-reductase 2 gene in the two siblings. Therefore, the absent or reduced expression of 5alpha-reductase 2 is likely to be additional to the AIS. Distinct phenotypic variation in this family was caused by 5alpha-reductase 2 deficiency, additional to AIS. This 5alpha-reductase deficiency is due to absence of expression of the 5alpha-reductase iso-enzyme 2 as shown by molecular studies. The distinct phenotypic variation in AIS here is explained by differences in the availability of 5alpha-dihydrotestosterone during embryonic sex differentiation.

Bone mineral density and body composition before and during treatment with gonadotropin-releasing hormone agonist in children with central precocious and early puberty.

Major changes in bone mineral density (BMD) and body composition occur during puberty. In the present longitudinal study, we evaluated BMD and calculated volumetric BMD [bone mineral apparent density (BMAD)], bone metabolism, and body composition of children (32 girls and 2 boys) with central precocious and early puberty before and during treatment with GnRH agonist (GnRH). Patients were studied at baseline and during treatment for 6 months (n = 34), 1 yr (n = 33), and 2 yr (n = 16). Lumbar spine and total body BMD and body composition were measured with dual-energy x-ray absorptiometry. The variables were compared with age- and sex-matched reference values of the same population and expressed as SD score (SDS). Bone age was assessed. Serum calcium, phosphate, alkaline phosphatase, osteocalcin, the carboxyterminal propeptide of type I collagen (PICP), cross-linked telopeptide of collagen I (ICTP), 1,25 dihydroxyvitamin D and urinary hydroxyproline/creatinine, and calcium/ creatinine ratios were measured. Mean lumbar spine BMD SDS was significantly higher than zero at baseline (P < 0.02) and did not differ from normal, after 2 yr of treatment. Mean spinal BMAD SDS and total body BMD SDS were not significantly different from zero at baseline and had not changed significantly after 2 yr of treatment. During therapy, fat mass and percentage body fat SDS increased, whereas lean tissue mass SDS decreased. Mean lumbar spine BMD and BMAD and total body BMD SDS, calculated for bone age, were all lower than zero at baseline (BMD P < 0.001 and BMAD P < 0.05) and also after 2 yr treatment (respectively, P < 0.001, P < 0.05, and P < 0.01). Biochemical bone parameters were significantly higher than prepubertal values at baseline, and they decreased during treatment. In conclusion, patients with central precocious and early puberty had normal BMD for chronological age but low BMD for bone age, after 2 yr of treatment with GnRH. Bone turnover decreased during treatment. Changes in body composition resembled those seen in patients with GH deficiency.

Body proportions during long-term growth hormone treatment in girls with Turner syndrome participating in a randomized dose-response trial.

To assess body proportions in girls with Turner syndrome (TS) during long term GH treatment, height, sitting height (SH), hand (Hand) and foot (Foot) lengths, and biacromial (Biac) and biiliacal (Biil) diameters were measured in 68 girls with TS participating in a GH dose-response trial. These previously untreated girls with TS, aged 2-11 yr, were randomly assigned to 1 of 3 GH dosage groups: group A, 4 IU/m2 x day; group B, first year 4 and thereafter 6 IU/m2 x day; group C, first year 4, second year 6, and thereafter 8 IU/m2 x day. Seven-year data were evaluated to assess the effect of GH treatment on body proportions during childhood. In addition, data from all girls who had reached adult height were evaluated to determine the effect on the adult body proportions. All results were adjusted for age and sex and expressed as SD scores using reference values of healthy Dutch girls. To describe the proportions of SH, Hand, Foot, Biac, and Biil to height, these values were adjusted for the SD score of height and were expressed as shape values, using the formula, e.g. for SH: shape SH = (SH SD score - height SD score)/square root(2 - 2 x correlation coefficient between SH and height in the reference population). Furthermore, SD scores using references of untreated girls with TS were calculated for height and SH. Values less than -2 or more than +2 were considered outside the normal range. At baseline, the shape values of all measurements were significantly higher than zero, but most mean shape values were still within the normal range. Seven-year data of 64 girls and adult height data of 32 girls showed that an increase in height was accompanied by an even higher increase in Foot, resulting in mean SD scores above zero and shape values of +2 and higher. The increase in the shape value of Foot was significantly higher in groups B and C compared to that in group A after 7 yr of GH treatment, but there were no significant differences between the GH dosage groups in the girls who had reached adult height. The shape values of SH had decreased to values closer to zero after reaching adult height, especially in group A. A similar pattern in the relationship of SH to height was seen using references of girls with TS. No significant changes in the other proportions were found after reaching adult height. In conclusion, on the average, untreated girls with TS have relatively large trunk, hands, and feet, and broad shoulders and pelvis compared to height. The increase in height after long term GH treatment is accompanied by an even higher increase in Foot and a moderate improvement of the disproportion between height and SH. Recently published reference data from untreated adults with TS and the results of a different patient group receiving a comparable GH dosage suggest that the disproportionate growth of feet has to be considered a part of the natural development in TS, but might be influenced by higher GH dosages. The development of large feet can play a role in the decision of the girl to discontinue GH treatment in the last phase of growth.

Levels of growth hormone, insulin-like growth factor-I (IGF-I) and -II, IGF-binding protein-1 and -3, and cortisol in prednisone-treated children with growth retardation after renal transplantation.

Growth retardation after renal transplantation (RTx) is generally attributed to prednisone (PDN) administration, although the exact mechanism is poorly understood. In a group of 19 growth-retarded post-RTx children, we studied the effect of alternate day (AD; n = 12) and daily (D; n = 7) PDN therapy (0.10-0.25 mg/kg.day) on 24-h plasma GH and cortisol profiles, once in group D and twice on successive days in group AD. The maximal plasma GH response to arginine provocation (ATT) and plasma levels of insulin-like growth factor-I (IGF-I), IGF-II, and serum IGF-binding proteins (IGFBP) were also determined. The pulsatile character of the 24-h GH secretion was sustained in all patients. However, mean GH levels were significantly lower as compared with published data for healthy children, corrected for pubertal stage and sex. The highest mean GH levels were found in boys and girls in late puberty. Group AD had similar 24-h GH profiles whether on or off PDN treatment, which did not differ significantly from the GH profiles observed in group D. The maximal GH response during ATT was greater than 10 micrograms/L in 57% of the children. Group D had significantly lower mean and maximal cortisol levels than group AD, but all patients had a normal diurnal variation. Plasma immunoreactive IGF-I and IGF-II, and serum IGFBP-1 levels were normal, but serum levels of IGFBP-3 were increased. A significant negative correlation was found between the glomerular filtration rate and serum IGFBP-3 levels. In conclusion, our findings indicate that growth-retarded renal allograft patients, receiving either alternate day or daily PDN therapy, have decreased GH secretion, but a normal diurnal rhythm of GH and cortisol secretion as well as normal plasma IGF-I and -II levels. However, growth retardation after RTx may not solely be the result of decreased GH secretion. Renal graft impairment together with decreased IGF bioavailability may, in addition to the presumed direct effects of PDN on cartilage, contribute to the growth retardation after RTx.

Carbohydrate metabolism during long-term growth hormone (GH) treatment and after discontinuation of GH treatment in girls with Turner syndrome participating in a randomized dose-response study. Dutch Advisory Group on Growth Hormone.

To assess possible side-effects of GH treatment with supraphysiological doses on carbohydrate (CH) metabolism in girls with Turner syndrome (TS) during long term GH treatment and after discontinuation of GH treatment, the results of oral glucose tolerance tests and hemoglobin A1c measurements were analyzed in 68 girls with TS participating in a randomized dose-response trial. These previously untreated girls, aged 2-11 yr, were randomly assigned to 1 of 3 GH dosage groups: group A, 4 IU/m2 x day (-0.045 mg/kg x day); group B, first year ,4 IU/m2 day; thereafter, 6 IU/m2 x day (approximately 0.0675 mg/kg x day); group C, first year, 4 IU/m2 x day; second year, 6 IU/m2 x day; thereafter, 8 IU/m2 x day (approximately 0.090 mg/kg x day). After the first 4 yr, girls 12 yr of age or older started with 5 microg/kg BW-day 17beta-estradiol for induction of puberty. To assess the effects of long term high dose GH treatment on CH metabolism, the 7-yr data from the oral glucose tolerance tests in 9 girls of group C were evaluated (group C1). To determine whether the changes in CH metabolism during GH treatment would persist after discontinuation of GH treatment, the data for 28 girls who had reached adult height (group A, n = 9; group B, n = 10; group C, n = 9) were evaluated at baseline, after 4 yr of GH treatment, and 6 months after discontinuation of GH. Seven-year data for group C1 showed that glucose levels did not significantly change during GH treatment, whereas fasting insulin levels as well as glucose-induced insulin levels increased significantly. The data for the 28 girls who were treated with GH for a mean (SD) period of 85.3 (13.3) months demonstrated that the GH-induced higher insulin levels decreased to values close to or equal to pretreatment values after discontinuation of GH treatment. Changes in CH variables were not significantly related to the GH dose. Hemoglobin A1c levels never showed an abnormal value. The prevalence of impaired glucose tolerance was low, and none of the girls developed diabetes mellitus. In conclusion, long term GH treatment with dosages up to 8 IU/m2 x day in girls with TS has no adverse effects on glucose levels, but induced higher levels of insulin, indicating relative insulin resistance. The increased insulin levels during long term GH treatment decreased after discontinuation of GH treatment to values close to or equal to pretreatment values. Although the reversibility of the effects of long term GH is reassuring, the consequence of long term hyperinsulinism is still unknown.