Efficacy and safety of growth hormone treatment in children with short stature: the Italian cohort of the GeNeSIS clinical study.

PURPOSE: We examined auxological changes in growth hormone (GH)-treated children in Italy using data from the Italian cohort of the multinational observational Genetics and Neuroendocrinology of Short Stature International Study (GeNeSIS) of pediatric patients requiring GH treatment. METHODS: We studied 711 children (median baseline age 9.6 years). Diagnosis associated with short stature was as determined by the investigator. Height standard deviation score (SDS) was evaluated yearly until final or near-final height (n = 78). Adverse events were assessed in all GH-treated patients. RESULTS: The diagnosis resulting in GH treatment was GH deficiency (GHD) in 85.5 % of patients, followed by Turner syndrome (TS 6.6 %). Median starting GH dose was higher in patients with TS (0.30 mg/kg/week) than patients with GHD (0.23 mg/kg/week). Median (interquartile range) GH treatment duration was 2.6 (0.6-3.7) years. Mean (95 % confidence interval) final height SDS gain was 2.00 (1.27-2.73) for patients with organic GHD (n = 18) and 1.19 (0.97-1.40) for patients with idiopathic GHD (n = 41), but lower for patients with TS, 0.37 (-0.03 to 0.77, n = 13). Final height SDS was >-2 for 94 % of organic GHD, 88 % of idiopathic GHD and 62 % of TS patients. Mean age at GH start was lower for organic GHD patients, and treatment duration was longer than for other groups, resulting in greater mean final height gain. GH-related adverse events occurred mainly in patients diagnosed with idiopathic GHD. CONCLUSIONS: Data from the Italian cohort of GeNeSIS showed auxological changes and safety of GH therapy consistent with results from international surveillance databases.

Primary Graft Dysfunction After Zero-Mismatch Kidney Transplantation Secondary to Early Biopsy-Proven Acute Cell-Mediated Rejection: Case Report.

We report a case of primary renal allograft dysfunction and early acute cell-mediated rejection after a 12/12 HLA antigen zero-mismatch (0MM) transplant. The recipient was a 40-year-old white man who was highly allosensitized, with a calculated panel reactive antibody score of 100%. In posteroperative day 1 the recipient remained anuric and underwent dialysis because of hyperkalemia. Graft biopsy showed early acute cellular rejection, Banff grade 2B. No evidence of antibody-mediated rejection was observed. To our knowledge, this case is the 1st to report early cell-mediated rejection after 12/12 HLA antigen 0MM kidney transplantation. This case suggests that highly sensitized candidates are at high immunologic risk even in the context of 0MM kidney transplantation.

Functional and structural analysis of four novel mutations of CYP21A2 gene in Italian patients with 21-hydroxylase deficiency.

Congenital adrenal hyperplasia (CAH) is an autosomal recessive disorder mainly caused by defects in the 21-hydroxylase gene (CYP21A2), coding for the enzyme 21-hydroxylase (21-OH). About 95% of the mutations arise from gene conversion between CYP21A2 and the inactive pseudogene CYP21A1P: only 5% are novel CYP21A2 mutations, in which functional analysis of mutant enzymes has been helpful to correlate genotype-phenotype. In the present study, we describe 3 novel point mutations (p.L122P, p.Q481X, and p.E161X) in 3 Italian patients with CAH: the fourth mutation (p.M150R) was found in the carrier state. Molecular modeling suggests a major impact on 21-hydroxylase activity, and functional analysis after expression in COS-7 cells confirms reduced enzymatic activity of the mutant enzymes. Only the p.M150R mutation affected the activity to a minor extent, associated with NC CAH. CYP21A2 genotyping and functional characterization of each disease-causing mutation has relevance both for treatment and genetic counseling to the patients.

Evidence for epigenetic abnormalities of the androgen receptor gene in foreskin from children with hypospadias.

CONTEXT: Hypospadias is a malformation of the penis due to an incomplete development of the male urethra, the exact etiology of which in the majority of cases remains unknown. OBJECTIVE: The objective of the study was to assess whether defects of the androgen receptor (AR) gene (CAG repeats and methylation pattern) and DNA methyltransferases (DNMT) family are present in hypospadic patients. DESIGN: CAG repeats length, methylation status, and expression of the AR gene were analyzed. The DNMT family was studied at the protein level and the DNMT3A sequenced. SETTING: The study was performed at a pediatric endocrinology referral clinic. PATIENTS OR OTHER PARTICIPANTS: Twenty boys with isolated glandular hypospadias and 20 age-matched control children undergoing a surgical procedure for circumcision were studied. MAIN OUTCOME MEASURE(S): CAG repeats length and AR methylation pattern in PBLs and foreskin tissue, DNMT expression and sequencing in patients and controls, and in vitro studies in cultured fibroblasts were measured. RESULTS: AR gene methylation in foreskin tissues from patients with hypospadias was higher than in normal children. AR expression in foreskin tissue of hypospadic patients was lower than in controls, whereas the DNMT3A protein level was significantly higher in patients than controls. In cultured fibroblasts, both dihydrotestosterone and testosterone significantly reduced AR gene methylation and DNMT3A expression in a dose-dependent fashion and increased AR expression. CONCLUSION: The AR gene in target tissues from patients with hypospadias is more methylated than in control children, resulting in a decreased expression of the AR. The mechanism underlying the modulation of the AR gene expression seems to be mediated by DNMT3A. This epigenetic alteration of the AR gene might be involved in the pathogenesis of hypospadias.

Heterozygous mutation of HESX1 causing hypopituitarism and multiple anatomical malformations without features of septo-optic dysplasia.

Isolated GH deficiency or combined pituitary hormone deficiencies have been associated with mutations in transcription factors encoding genes that control organogenesis or cell differentiation. Among these factors, Hesx1 is essential for the development of the optic nerve and regulates some of the earliest stages in pituitary development and is intimately involved in orchestrating the expression of other factors involved in pituitary organogenesis. Mutations in HESX1 are reported in patients with hypopituitarism either with typical septo-optic dysplasia (SOD) or with neuromorphological abnormalities not included in classical SOD. The present report describes clinical features, biochemical parameters, and characterization of a missense mutation (Gln6His) in exon1 of HESX1 in a pre-pubertal child who progressively developed multiple hypopituitarism, firstly GH and, afterwards, TSH and ACTH deficiencies, in a pluri-malformative syndrome characterized by short stature and anatomical malformations not associated with a classical SOD phenotype. This finding further supports the necessity to stay alert in evaluating a gene that plays a minor role in the pathogenesis of sporadic hypopituitarism, such as HESX1 gene even when the phenotype does not fit in with a classical SOD syndrome.

Aromatase is differentially expressed in peripheral blood leukocytes from children, and adult female and male subjects.

OBJECTIVE: Aromatase, the key enzyme involved in estrogen synthesis, is expressed in a variety of cells and tissues including human peripheral blood leukocytes (PBLs). The present study was designed to evaluate PBL aromatase gene expression in male and female subjects of different age groups. In addition, differences in gene expression during the follicular and luteal phase of the menstrual cycle in women, and before and after testosterone administration in men, were estimated. DESIGN: Aromatase mRNA and protein were measured in PBLs obtained from young (n = 10) and postmenopausal women (n = 10), men (n = 15), and prepubertal children (n = 10). Aromatase mRNA and protein were also measured during the follicular and luteal phases of the menstrual cycle in women, and before and after the intramuscular administration of 250 mg testosterone enanthate in men. METHODS AND RESULTS: Aromatase mRNA measured by real-time PCR in PBLs from women during the follicular phase was significantly higher than during the luteal phase of the menstrual cycle (P < 0.05). In men, PBL aromatase mRNA values increased significantly following testosterone administration (P < 0.05). PBL mRNA aromatase levels in women during the follicular phase and men after testosterone administration were significantly higher (one-way ANOVA; P < 0.05) than in any other group. Children, postmenopausal women, and women during the luteal phase showed the lowest aromatase mRNA expression. The results of the immunoblot analysis confirmed the data obtained by real-time PCR. A positive correlation between PBL aromatase mRNA values and plasma estradiol and estrone levels during the follicular phase of the menstrual cycle was observed in the group of adult women. No other correlations were found. CONCLUSIONS: The aromatase gene is differentially expressed in PBLs from women, men, and prepubertal children, indicating a sexual dimorphism in the enzyme expression and an important role of sex steroids in the modulation of aromatase gene expression.

Decreased androgen receptor gene methylation in premature pubarche: a novel pathogenetic mechanism?

CONTEXT: Several studies found links between DNA methylation and gene expression. In patients with idiopathic hirsutism, a preferential methylation of the of shorter androgen receptor (AR) alleles was hypothesized to be responsible for the abnormal hair growth. OBJECTIVE: The objective of this study was to assess whether abnormalities in the AR function in both peripheral blood leukocytes (PBLs) and androgen target tissues are present in children with premature pubarche (PP). DESIGN: Human DNA was extracted from PBLs and pubic hair and CAG repeats length and methylation status of the AR gene were analyzed. SETTING: The study was performed at a Pediatric Endocrinology referral clinic. PATIENTS: Twenty-five girls with PP, 23 prepubertal children, and 10 girls with Tanner stage II pubertal development were studied. MAIN OUTCOME MEASURE: The main outcome measures were CAG repeat length and AR methylation pattern in PBLs and pubic hair. RESULTS: In PBLs from PP patients, AR gene methylation was significantly lower (P < 0.01) than that of prepubertal children and similar to that of girls with Tanner II stage pubertal development. A negative correlation between AR gene methylation in PBLs and the age of normal children was detected. PATIENTS with PP exhibited a hair follicle AR methylation pattern similar to that of Tanner stage II girls. The mean number of CAG repeats was lower in PP patients than in prepubertal and Tanner stage II girls, although it was within the normal range for the general population in both groups. CONCLUSIONS: The increased AR gene activity observed in PP patients, as indicated by the reduced AR gene methylation pattern, together with the presence of shorter CAG repeats, might lead to hypersensitivity of the hair follicles to steroid hormones and therefore to the premature development of pubic hair.

Relative abundance of growth hormone receptor isoforms in rhesus monkey tissues and human transformed lymphocytes.

The growth hormone receptor (GHR) is expressed as one active, full-sequence isoform and one truncated, inactive one that lacks the intracellular signaling domain. The aim of this study was to investigate the variation in the tissue expression of the full and truncated mRNA and protein. Epstein-Barr virus-transformed human B lymphocyte lines were established from 9 normal individuals with a height standard deviation score (SDS) of - 0.1 +/- 1.1 (mean +/- SD). Tissues were also collected from 3 Rhesus monkeys, whose GHR has 94.1 % homology with the human molecule. mRNA quantitation was determined by Real Time Quantitative PCR. Growth hormone receptor expression in transformed lymphocytes was also studied by fluorescence-activated cell sorter analysis. Both isoforms were expressed in transformed lymphocytes, but individual variation in the relative mRNA expression was small (truncated isoform percentage of total receptor mRNA: 17.1 +/- 4.4, mean +/- SD). There was no correlation between donors' height SDS and the expression of either isoform or the ratio between them. Protein expression by FACS analysis showed wider variation among the subjects; however, the relative ratio was similar in all the subjects. In monkey tissues, the truncated receptor showed a tissue-specific distribution. In conclusion, the expression of both isoforms in transformed lymphocytes from normal subjects shows small differences at the RNA or protein levels, and does not correlate with height SDS. Growth hormone splice isoforms show tissue specificity, suggesting local regulation of splicing. Tissues with relatively high expression of the truncated isoform are likely to be more resistant to the effects of GH due to the dominant negative effect of this isoform. In addition, the differential tissue expression might influence the levels of growth hormone binding protein in the immediate milieu of each tissue.

Transcriptional and translational regulation of the splicing isoforms of the growth hormone receptor by glucocorticoids.

Glucocorticoids exert multiple effects on the growth hormone IGF-I axis. The GH receptor is expressed as an active, full-sequence molecule and a truncated, inactive one that lacks the intracellular signaling domain. We used the HuH7 human hepatoma cell line to investigate the effect of glucocorticoids on growth hormone receptor mRNA and protein expression. cDNA quantification was performed by Real Time Quantitative PCR. Growth hormone receptor expression at the protein level was studied by fluorescence-activated cell sorter analysis using specific polyclonal antibodies raised against the two isoform unique C-terminal sequences. Cells were treated with pharmacologic doses of dexamethasone (Dex 10 -7 - 10 -5 M) to assess its acute (1 hour or overnight) and chronic effects (7 days). Dex induced a dose-dependent increase of both the full (427 %) and truncated (180 %) mRNAs. At the protein level, Dex upregulated the full sequence more (183 %) than the truncated (126 %) protein. For a better understanding of this regulation system, cells were incubated with Dex 10 -6 M for 24 h in the absence or presence of a transcriptional inhibitor, actinomycin D, or a translational inhibitor, cycloheximide. Actinomycin D had no effect on Dex-induced upregulation, while cycloheximide blocked the truncated mRNA but not the full sequence mRNA upregulation, suggesting that this effect of glucocorticoids is a post-transcriptional event. After 7 days of chronic treatment, Dex induced a dose-dependent downregulation of the active receptor without any changes in the expression of the truncated isoform either at the mRNA or protein levels. We conclude that short-term glucocorticoid treatment results in an enhancement of the growth hormone receptor expression, while long-term treatment has a suppressive effect, through both transcriptional and translational mechanisms ultimately influencing both isoforms of the receptor.

Hormonal regulation of interleukin-6 production in human adipocytes.

OBJECTIVE: To elucidate the hormonal regulation of interleukin-6 (IL-6) production by human adipose tissue and its relation to leptin. DESIGN: In vitro study. Human adipocytes were incubated with dexamethasone (with or without RU486), norepinephrine and epinephrine (with or without propranolol), or insulin. MEASUREMENTS: IL-6 and leptin secretion by human adipocytes. RESULTS: A gradual increase in IL-6 secretion by adipocytes during differentiation was observed. A positive correlation was found between basal IL-6 release and both glycerol 3-phosphate dehydrogenase activity--a marker of adipocyte differentiation-and leptin release. Dexamethasone decreased IL-6 secretion and increased leptin secretion in a dose-dependent manner. Both catecholamines increased IL-6 and leptin secretion. The effects of dexamethasone and catecholamines on IL-6 and leptin were abrogated by RU486 and propranolol, respectively. Incubation with insulin resulted in a dose-dependent stimulation of IL-6 and leptin secretion. CONCLUSIONS: IL-6 is produced by human adipocytes and is a potential marker of adipocyte differentiation. Furthermore it is a hormonally regulated cytokine, suppressed by glucocorticoids, and stimulated by catecholamines and insulin in physiological concentrations.

Leptin, cortisol, and GH secretion interactions in short normal prepubertal children.

The hormonal regulation of the ob gene and leptin secretion in humans is still unclear. To investigate the interactions among leptin, cortisol, and GH, we analyzed and time-cross-correlated their spontaneous 24-h secretion in 12 short normal prepubertal children of both sexes (6 females and 6 males). Time-cross-correlation analyses demonstrated that leptin and cortisol were correlated in both a negative and positive fashion. The negative correlation, with cortisol leading leptin by 4 and 3 h for boys and girls, respectively, might reflect the stimulatory effect of CRH on the sympathetic system, which inhibits leptin secretion; the positive correlation, with leptin leading cortisol by 6 and 5 h for boys and girls, respectively, might reflect a direct effect of leptin on CRH secretion in the hypophyseal portal system. Time-cross-correlation analyses also showed a strong positive correlation between GH and leptin concentrations, with GH leading leptin by 5 and 2 h for boys and girls, respectively, suggesting a possible direct leptin-releasing effect of GH on adipocytes. We conclude that cross-correlation analyses of 24-h hormone secretions under baseline physiological conditions suggest that the hypothalamic-pituitary-adrenal axis might have a prevailing inhibitory effect on leptin secretion, whereas leptin might exert a positive effect on the hypothalamic-pituitary-adrenal axis. The relation between GH and leptin could be a direct one and characterized prevalently by a positive effect of GH on leptin secretion. Further investigations using different experimental systems are needed to ascertain the validity of these mathematically educed conclusions.

Leptin inhibits steroid biosynthesis by human granulosa-lutein cells.

Absence of leptin secretion compromises reproductive function and fertility in the ob/ob mouse which, when given leptin, shows a rise in serum LH levels and becomes fertile. Recently, the long and active isoform of the leptin receptor was detected in the ovary, indicating that leptin may also show direct gonad-related activity. To examine this, we studied the effect of graded doses of human leptin on estradiol (E2) and progesterone (P4) concentrations in the culture media of human granulosa-lutein cells obtained from follicular fluid of women undergoing in vitro fertilization. We also evaluated the mRNA expression of steroidogenic acute regulatory protein (StAR), aromatase, and cytochrome P450 17alpha (CYP17) in these cells at baseline and after exposure to leptin. Estradiol levels were significantly decreased in the media 24 hours after incubation of the cells with increasing hLeptin concentrations (10(-11) - 10(-7) mol/l). The maximal 30% decrease in E2 production was caused by the 10(-9) mol/l hLeptin concentration; however, P4 levels in the media were not influenced by leptin. Exposure of granulosa-lutein cells to 10(-9) mol/l hLeptin did not produce any measurable changes on StAR, aromatase, or CYP17 mRNA expression. When hLeptin (10(-9) mol/l) was co-incubated with increasing concentrations of hCG (1.25 - 10 mlU/ml), IGF-II (15-60 ng/ml) or 1-6 desaminated IGF-II (deslGF-II; 15-60 ng/ml), it did not modify the elevation of E2 concentrations caused by each of the different stimuli. We conclude that leptin suppresses E2 secretion by human granulosa-lutein cells but does not impair the stimulatory effects of hCG and IGFs on these cells. Leptin may play a minor, but direct regulatory role on unstimulated human ovarian steroidogenesis by interfering with either the translational or post-translational steps of the baseline CYP17 and/or aromatase synthesis and/or the activation of the enzymes.

Interactions of leptin and thyrotropin 24-hour secretory profiles in short normal children.

Thyroid hormones and leptin have effects on similar aspects of body homeostasis, such as energy expenditure, thermogenesis, and metabolic efficiency. Thus, the cross-talk between the thyrostat and the lipostat might play a crucial role in the maintenance of body homeostasis. To investigate the relationship between the hypothalamic-pituitary-thyroid (HPT) axis and leptin under physiological conditions, we evaluated the pulsatility and circadian rhythmicity and time-cross-correlated the 24-h secretory patterns of leptin and TSH in 12 short normal prepubertal children (6 girls and 6 boys). In both male and female subjects, leptin was secreted in a pulsatile and circadian fashion, with a nocturnal leptin surge that was more pronounced in males than in females. Mean 24-h leptin levels and total area under the curve were significantly higher in girls than in boys. This was mainly due to the nighttime mean leptin levels and total area under the curve, which were higher than those in boys. The cross-correlated 24-h leptin and TSH levels revealed significant positive and negative correlations. The positive one, of leptin over TSH, suggests a positive feedback regulation by leptin on the HPT axis, which might play an important role in triggering the neuroendocrine response to starvation, including decreased thyroid hormone levels. The negative correlation, of TSH over leptin, could explain the compensatory changes in adipocyte metabolism, and indirectly in circulating leptin levels, in response to alterations in thyroid status. In conclusion, we suggest that under baseline physiological conditions, the HPT axis has a prevailing inhibitory effect on leptin secretion, whereas leptin has a prevailing positive effect on the HPT axis. The sexual dimorphism in leptin levels does not seem to influence in a major way the interactions between the HPT axis and leptin.

High constitutive glucocorticoid receptor beta in human neutrophils enables them to reduce their spontaneous rate of cell death in response to corticosteroids.

Neutrophils are markedly less sensitive to glucocorticoids than T cells, making it difficult to control inflammation in neutrophil-mediated diseases. Development of new antiinflammatory strategies for such diseases would be aided by an understanding of mechanisms underlying differential steroid responsiveness. Two protein isoforms of the human glucocorticoid receptor (GR) exist, GRalpha and GRbeta, which arise from alternative splicing of the GR pre-mRNA primary transcripts. GRbeta does not bind glucocorticoids and is an inhibitor of GRalpha activity. Relative amounts of these two GRs can therefore determine the level of glucocorticoid sensitivity. In this study, human neutrophils and peripheral blood mononuclear cells (PBMCs) were studied to determine the relative amounts of each GR isoform. The mean fluorescence intensity (MFI) using immunofluorescence analysis for GRalpha was 475 +/- 62 and 985 +/- 107 for PBMCs and neutrophils, respectively. For GRbeta, the MFI was 350 +/- 60 and 1,389 +/- 143 for PBMCs and neutrophils, respectively (P < 0.05). After interleukin (IL)-8 stimulation of neutrophils, there was a statistically significant increase in intensity of GRbeta staining to 2,497 +/- 140 (P < 0.05). No change in GRalpha expression was observed. This inversion of the GRalpha/GRbeta ratio in human neutrophils compared with PBMCs was confirmed by quantitative Western analysis. Increased GRbeta mRNA expression in neutrophils at baseline, and after IL-8 exposure, was observed using RNA dot blot analysis. Increased levels of GRalpha/GRbeta heterodimers were found in neutrophils as compared with PBMCs using coimmunoprecipitation/Western analysis. Transfection of mouse neutrophils, which do not contain GRbeta, resulted in a significant reduction in the rate of cell death when treated with dexamethasone.We conclude that high constitutive expression of GRbeta by human neutrophils may provide a mechanism by which these cells escape glucocorticoid-induced cell death. Moreover, upregulation of this GR by proinflammatory cytokines such as IL-8 further enhances their survival in the presence of glucocorticoids during inflammation.

Low glucocorticoid receptor alpha/beta ratio in T-cell lymphoblastic leukemia.

Glucocorticoid therapy is pivotal in the treatment of acute lymphoblastic leukemia (ALL); it reduces cell proliferation, promotes cell cycle arrest, and induces cell death by apoptosis. The sensitivity of leukemic cells to glucocorticoids was previously related to the cell concentration of 3[H]dexamethasone-binding sites. The latter represents the classic glucocorticoid receptor (GR) isoform alpha that binds ligand and modulates the transcription rates of glucocorticoid-responsive genes. In ALL, lymphoblasts of T-lineage are less sensitive to glucocorticoids than cells of the B-lineage. The alternatively spliced GR isoform (GRP), which exerts a dominant negative effect on GRalpha-mediated transcriptional activity, has been proposed as a possible mediator of glucocorticoid resistance. In this study, we determined the amount of GRalpha and GRbeta in mononuclear cells from 13 newly diagnosed and untreated children with ALL and 9 controls by quantitative Western analysis. Generally, leukemic patients expressed 6 times less GRalpha (ALL= 0.54 +/- 1.1; controls = 3.1 +/- 0.9; p < 0.01) than controls, but the same amount of GRbeta (ALL=3.62 +/- 3.3; controls = 3.6 +/- 3.4). ALL patients with T-cell disease had a much lower GRalpha (0.09 +/- 0.1; p < 0.01) but a similar or slightly higher GRbeta (5.98 +/- 3.9; p = 0.1) expression than controls, with a GRalpha/GRbeta ratio 15 times smaller than controls. Mononuclear leukocytes of T-cell lineage expressed significantly lower GRalpha (p = 0.04) and higher GRbeta (p < 0.01) than cells of the pre-B immunophenotype, with a 10 times smaller ratio. We conclude that the combination of low GRalpha and normal-to-high GRbeta expression in leukemic lymphoblasts might represent one of the mechanisms responsible for their reduced glucocorticoid sensitivity; this is more pronounced in T-lineage cells.

Long-term results with growth hormone therapy in idiopathic hypopituitarism.

More than 30 years after its introduction, growth hormone (GH) treatment is well established in children with GH deficiency. Nevertheless, the long-term results of this therapy, expressed as height, are generally considered unsatisfactory. We report on results obtained in a group of GH-deficient children who were treated with daily injections of recombinant GH within the first 5 years of life and who reached an adult height very close to their target height. The full catch-up growth to the target height demonstrated in these patients suggests that replacement therapy should be started early and continued until adulthood. Height at onset of puberty is an important variable which might significantly influence the adult height. The significant and prolonged influence of birth weight on growth response to GH therapy underlines the important role of fetal growth in planning early treatment of GH-deficient children.

[Premature pubarche]. / Il pubarca prematuro.

Premature adrenarche refers to the appearance of public hair before age 8 years in girls and 9 years in boys, without other signs of puberty or virilization. Growth velocity may be increased and slightly advanced bone maturation is often present and is usually well correlated with the height age. The transient acceleraration of growth and of bone maturation have no negative effects on the onset and progression of puberty, and on final height. The diagnosis is based on the exclusion of the different forms of hyperandrogenism such as precocious puberty, late-onset congenital adrenal hyperplasia, virilizing tumors, glucocorticoid resistance, and Cushing syndrome. Once the diagnosis is made, no treatment is needed. However, a long-term follow-up of these patients is warranted. Recent data, in fact, indicate that girls with premature adrenarche may not have a benign outcome. Postpubertal girls with premature adrenarche during childhood have an increased frequency of functional ovarian hyperandrogenism. Furthermore, hyperinsulinemia is a common feature in adolescent patients with premature adrenarche and functional ovarian hyperandrogenism, and appears to be directly realted to the degree of androgen excess. Although the mechanisms interlinking the triad of premature pubarche, hyperinsulinemia and ovarian hyperandrogenism remain enigmatic, this frequent concurrence may result, at least in part, from a common early origin rather than from a direct interrelationship later in life.

Androgen receptor-mediated hypersensitivity to androgens in women with nonhyperandrogenic hirsutism: skewing of X-chromosome inactivation.

Idiopathic hirsutism may result from an increase in the androgen receptor (AR)-mediated sensitivity of the hair follicle. The AR gene is located on the X-chromosome and contains a highly polymorphic trinucleotide repeat (CAGn) in its first exon, whose length and methylation pattern affect both AR expression and function. We analyzed these CAG repeats in the genomic DNA from 16 nonhyperandrogenic hirsute patients (Ferriman score: 16 +/- 4.7, mean +/- SD) and 10 normal controls (Ferriman score: 3 +/- 1.4), who were similar in their hormonal profiles. We found no difference in the number of CAG repeats between hirsute patients and controls, and no correlation between number of repeats and the Ferriman score or hormonal values. However, after DNA digestion with methylation-sensitive HpaII and measurement of the optical density, we found a marked decrease in the hirsute group (P < 0.0001), which was greater than in the control group (P = 0.0003). In addition, in the hirsute patients, the shorter of the two alleles was preferentially less methylated (P = 0.007), suggesting skewing of X-chromosome inactivation in the patients but not in the controls. When the mean optical density of both alleles was correlated with the Ferriman score, we observed a significant negative correlation (P = 0.02, r = -0.45), which became stronger when the shorter alleles were analyzed separately (P = 0.01; r = 0.48). We conclude that nonhyperandrogenic hirsutism is associated with skewing of X-chromosome inactivation in peripheral blood lymphocytes. This leads to the longer of the two AR alleles being preferentially methylated, allowing for the shorter (and presumably, more functional) allele to be expressed on the active X-chromosome. Further studies need to be performed to investigate whether this phenomenon is present in androgen-sensitive tissues in these patients.