The E180splice mutation in the GHR gene causing Laron syndrome: witness of a Sephardic Jewish exodus from the Iberian Peninsula to the New World?

Laron syndrome (LS) is a genetic disorder caused by mutations in the growth hormone receptor (GHR) gene. The most frequent GHR mutation is E180splice (rs121909360), which was initially found in an inbred population of Spanish descent in Ecuador and subsequently in Israel, Brazil, Chile, and the United States. The aim of the present study is to determine if the E180splice mutation arose from a common origin. We studied 22 patients with LS from Ecuador, Israel (of Moroccan origin), Brazil, Chile, and the United States (of Mexican origin) who were homozygous for the E180splice mutation and compared them to control individuals for markers surrounding the GHR, intragenic polymorphisms, and Y-chromosome STR. An identical haplotype was found in all but one of the subjects carrying the E180splice mutation: D5S665: 150/150; D5S2082: 192/192; D5S2087: 246/246; rs6179 G/G; and rs6180 C/C. One patient differed from the others only at D5S2082 (168/192). This haplotype is rare (~1%) in control individuals and confirmed that the E180splice-associated haplotype was not derived from independent origins but represented recombination from a common ancestor. The analysis of paternal lineage markers showed that 50% belong to haplogroup R1b (found in Portugal and Spain) and 40% to haplogroups J and E (typical in the Middle East and in Eastern European Jews). The germline E180Splice mutation appears to have originated from a single common ancestor. The presence of Y-chromosome markers associated with Sephardic populations in persons harboring the E180splice mutation provides genetic evidence in support of the historical tracking of the exodus of this specific population.

Molecular characterization of Chilean patients with a clinical diagnosis of Noonan syndrome

BACKGROUND

Noonan syndrome (NS) is an autosomal dominant syndrome characterized by typical dysmorphic features, cardiac anomalies as well as postnatal growth retardation, and is associated with Ras-MAPK pathway gene mutations. The purpose of this study was to improve the diagnosis of Chilean patients with suspected NS through molecular analysis.

METHODS

We screened 18 Chilean patients with a clinical diagnosis of NS for mutations in PTPN11 by high resolution melting (HRM) and subsequent sequencing.

RESULTS

Three PTPN11 missense mutations were detected in 22% of analyzed patients. Of these, two (c.181G>A and c.1510A>G) were previously reported and one was the novel substitution c.328G>A (p.E110K) affecting the linker stretch between the N-SH2 and C-SH2 domains of SHP-2 protein.

CONCLUSION

Molecular studies confirmed the clinical diagnosis of NS in 4 of 18 patients, which provided support for therapeutic decisions and improved genetic counseling for their families.

Effects of thyroid hormone on the GH signal transduction pathway

BACKGROUND/AIM

The importance of thyroid hormone on growth and development in children is well recognized. In addition, linear growth is highly dependent on the response of peripheral tissues to growth hormone, a process known as GH sensitivity, but little is known about the possible effects of T4 on this process.

METHODS

We determined the effect of stimulation with recombinant human GH (rhGH; 200 ng/mL) alone or in combination with two different concentrations of T4 (250 nM and 500 nM for 24 h) on JAK2 and STAT5 activation in skin fibroblast cultures obtained from prepubertal boys with normal height.

RESULTS

JAK2 and STAT5 were activated under co-incubation with T4 (at both concentrations) and rhGH in the non-nuclear fraction of the fibroblasts. In addition, after 24h of co-incubation with rhGH and T4 (500 nM), we observed an increase in phospho-STAT5 in the nuclear fraction, when compared to GH and T4 stimulation alone. This effect was not observed when the fibroblasts were co-incubated with GH and the lower concentration of T4 (250 nM).

CONCLUSION

Combined stimulation with GH and T4 at a concentration of 500 nM increases synergistically nuclear phospho-STAT5 in skin fibroblasts, which may amplify tissue sensitivity to GH. These findings may help to explain the effect of T4 administration on growth velocity in some children with idiopathic short stature.

Promoting excellence in the care of pediatric endocrine diseases in the developing world

On behalf of the Global Pediatric Endocrinology and Diabetes group, the authors provide a perspective on the rights of a child as enshrined in the United Nations Convention on the Rights of the Child (1989) concerning the care of pediatric endocrine disorders and diabetes mellitus, throughout the world, with particular reference to care in resource-constrained settings. In this article, we define the spectrum of health care needs of the child with an endocrine disorder and how they may be addressed, in terms of education, research, and development of sustainable programs for improved health outcomes. We emphasize the responsibilities of medical communities, the pharmaceutical industry, and relevant governments in promoting and supporting such concepts.

Clinical and molecular characterization of Chilean patients with Léri-Weill dyschondrosteosis

AIM

Léri-Weill dyschondrosteosis (LWD) is a mesomelic dysplasia with disproportionate short stature associated with short stature homeobox-containing gene (SHOX) haploinsufficiency. The objective of this study was to improve the diagnosis of patients with suspected LWD through molecular analysis.

METHODS

Twelve patients from 11 families with a clinical diagnosis of LWD were analyzed with multiplex ligation-dependent probe amplification to detect deletions and duplications of SHOX and its enhancer regions. High resolution melting and sequencing was employed to screen for mutations in SHOX coding exons.

RESULTS

The molecular-based screening strategy applied in these patients allowed detection of five SHOX deletions and two previously unreported SHOX missense mutations.

CONCLUSION

Molecular studies confirmed the clinical diagnosis of LWD in seven out of 12 patients, which provided support for therapeutic decisions and improved genetic counseling in their families.

Phosphotyrosine phosphatases in GH-stimulated skin fibroblasts from children with idiopathic short stature

AIM

Some cases of idiopathic short stature (ISS) may be caused by defects in the modulation of the negative feedback regulation of the growth hormone receptor (GHR)/ Janus kinase (JAK)2/signal transducers and activators of transcription (STAT)5 signaling pathway. The cytosolic tyrosine phosphatases, protein tyrosine phosphatase 1B (PTP1B) and Src homology 2 (SH2) domain-containing protein-tyrosine phosphatase-1 (SHP-1), the later which translocates to the nucleus after activation, interact with JAK2 in a GH-dependent manner. The possible contribution of PTP1B and SHP-1 to GH signaling in fibroblasts from ISS patients has not been studied.

METHODS

We determined the basal protein content of PTP1B and SHP-1 in the presence of recombinant human GH (rhGH) for 24 h in skin fibroblast cultures, obtained from patients with ISS, and were compared with a normal height control children group. JAK2 activation was determined in both groups.

RESULTS

JAK2 activation was delayed in fibroblasts from ISS patients compared to controls. Under basal conditions, the protein content of SHP-1 was lower in ISS, and after incubation with rhGH, it decreased in the non-nuclear and nuclear fraction of controls, but not in ISS patients. The protein content of PTP1B, however, increased in a similar fashion in fibroblasts from both ISS and control children.

CONCLUSION

The delayed activation of JAK2 and the lack of response of SHP-1 after incubation with GH in fibroblasts from ISS patients, suggests that the growth retardation observed in some of these children may be mediated in part by this phosphotyrosine phosphatase.

A rational approach to the diagnosis of polycystic ovarian syndrome during adolescence

Polycystic ovarian syndrome (PCOS) is a lifelong disorder characterized by hyperandrogenism and ovulatory dysfunction, with a wide spectrum of clinical symptoms and signs. Three different sets of diagnostic criteria have been established in order to define this disease in adult women, but there is controversy regarding the use of these criteria in adolescence. During puberty, the adult criteria for ovulatory dysfunction does not seem applicable, because an irregular menstrual pattern and a decreased ovulatory rate is a physiologic event during this period of life. Also, a higher prevalence of polycystic ovarian morphology (PCOM) may be observed during this period, so PCOM is not a useful criterion to define PCOS in young women. These findings suggest that a key factor to diagnose to PCOS during adolescence is hyperandrogenism. In addition, since PCOM is not clearly associated with hyperandrogenism during this period of life, the term "polycystic ovarian syndrome" during adolescence creates confusion and may be misleading.

A prospective cohort study of the prevalence of growth, facial, and central nervous system abnormalities in children with heavy prenatal alcohol exposure

BACKGROUND

Most children who are exposed to large quantities of alcohol in utero do not develop fetal alcohol syndrome (FAS). Population-based prospective data on the risk of developing components of fetal alcohol spectrum disorders (FASD), however, are limited.

METHODS

This was a prospective cohort study of 9,628 women screened during their first prenatal appointment in Chile, which identified 101 who consumed at least 4 drinks/d (exposed) matched with 101 women with no reported alcohol consumption during pregnancy (unexposed). Detailed alcohol consumption data were collected during the pregnancy. Children were evaluated up to 8.5 years of age by clinicians masked to exposure status.

RESULTS

One or more functional central nervous system abnormalities were present in 44.0% (22/50) of the exposed children compared to 13.6% (6/44) of the unexposed (p = 0.002). Growth restriction was present in 27.2% (25/92) of the exposed and 12.5% (12/96) of the unexposed (p = 0.02). Abnormal facial features were present in 17.3% (14/81) of the exposed children compared to 1.1% (1/89) of the unexposed children (p = 0.0002) by direct examination. Of the 59 exposed children with data available to detect at least 1 abnormality, 12 (20.3%) had no abnormalities. Binge drinking from conception to recognition of pregnancy (OR = 1.48 per day, 95% CI: 1.15 to 1.91, p = 0.002) and after recognition of pregnancy (OR= 1.41 per day, 95% CI: 1.01 to 1.95, p = 0.04) and total number of drinks consumed per week from conception to recognition of pregnancy (OR = 1.02 per drink, 95% CI: 1.01 to 1.04, p = 0.0009) were significantly associated with abnormal child outcome.

CONCLUSIONS

After exposure to heavy alcohol consumption during pregnancy, 80% of children had 1 or more abnormalities associated with alcohol exposure. Patterns of alcohol use that posed the greatest risk of adverse outcomes were binge drinking and high total weekly intake. Functional neurologic impairment occurred most frequently and may be the only sign to alert physicians to prenatal alcohol exposure.

Relationship between anti-Müllerian hormone (AMH) and insulin levels during different tanner stages in daughters of women with polycystic ovary syndrome

CONTEXT

We have previously described increased serum levels of anti-Müllerian hormone (AMH) and stimulated insulin in daughters of women with polycystic ovary syndrome (PCOS), suggesting that these girls may have an altered ovarian follicular development which may be modulated by insulin. However, the specific relationship between serum AMH and insulin levels during each Tanner stage of puberty in this cohort has not been established.

OBJECTIVE

The aim of our study was to establish the relationship between AMH and poststimulated insulin serum concentrations during each stage of puberty in daughters of women with PCOS (PCOSd), compared to daughters of control women (Cd).

DESIGN

We studied 135 PCOSd and 93 Cd classified according to their Tanner stage. Gonadotrophins, sex steroids, sex hormone-binding globulin (SHBG), and AMH were determined in a fasting sample. Ovarian volume was measured by pelvic ultrasound. In addition, in both groups we performed an oral glucose tolerance test with measurements of glucose and insulin.

RESULTS

Anti-Müllerian hormone levels were significantly higher in PCOSd compared to Cd at all Tanner stages. Daughters of women with PCOS having AMH concentrations greater than 2 standard deviation (SD) above the mean AMH value for the Cd group showed decreased serum follicle-stimulating hormone (FSH) concentrations and increased stimulated levels of insulin during Tanner stages I, II, and III.

CONCLUSIONS

Anti-Müllerian hormone levels are increased in PCOSd during all stages of puberty. We suggest that those PCOSd with the highest AMH levels probably represent a group of girls with more severe ovarian dysfunction and metabolic derangements.

Androgen receptor CAG and GGN polymorphisms in boys with isolated hypospadias

BACKGROUND

The etiology of hypospadias is multifactorial. Abnormal androgenic secretion and/or action during the development of external genitalia may be involved in the etiology of this congenital malformation. This study explored CAG and GGN polymorphisms in the androgen receptor (AR) gene, which may affect its transcriptional activity, in patients with isolated hypospadias.

METHODS

The length of the CAG/GGN polymorphisms was determined in 44 boys with non-severe (glandular) or severe (penile or penoscrotal) isolated hypospadias and with a normal hormonal evaluation. In addition, 79 healthy men, as controls, were studied.

RESULTS

Mean CAG repeats were significantly higher in total and severe cases compared to controls (24.4 +/- 2.8 and 24.7 +/- 3.1 vs. 22.7 +/- 3.3, respectively; p<0.05, Student's t and Bonferroni test). In addition, a frequency of CAG alleles >23 was significantly different in total and severe cases compared to controls (70.5% and 74.1% vs. 39.2%, respectively, p<0.05, chi2 and Bonferroni test). The median number and the distribution of GGN polymorphisms were similar in cases and controls.

CONCLUSION

Boys with isolated hypospadias have longer CAG alleles in their AR, which may be related with the development of this congenital malformation.

Polymorphisms of MAMLD1 gene in hypospadias

PURPOSE

Mastermind-like domain containing 1 (MAMLD1) is a causative gene for the fetal development of male external genitalia. Almost 10% of patients with both severe and non-severe hypospadias exhibit mutations of MAMLD1. The aim of this work was to determine whether polymorphisms of MAMLD1 are a genetic risk factor for hypospadias.

MATERIAL AND METHODS

This study included 150 hypospadias with a range of severities and 150 controls. Direct sequencing of the MAMLD1 coding exons and their flanking splice sites was performed. In silico secondary and tertiary structure prediction and accessibility of changed amino acids were evaluated using JPred, Netsurf and PHYRE software. Functional studies of the transactivation of haplotypes on Hes3 promoter were performed in vitro using cDNAs of missense variants of MAMLD1.

RESULTS

The p.P286S polymorphism was identified in 17/150 patients and 12/150 controls (11.3% vs. 8.0%, p = 0.32). The p.N589S polymorphism was identified in 22/150 patients and 12/150 controls (14.6% vs. 8.0%, p = 0.068). The double polymorphism (S-S haplotype) was present in 16/150 patients and 6/150 controls (10.6% vs. 4.0%, p = 0.044, OR = 2.87, CI from 1.09 to 7.55). The association of polymorphisms consistently revealed a modification in the structure prediction or amino acid accessibility in all three in silico models. The P286S, N589S and P286S + N589S proteins did not exhibit reduced transactivating activity on Hes3 promoter.

CONCLUSION

Polymorphisms of MAMLD1 gene are frequent in patients with hypospadias. Although no change in transactivation was noted on Hes3 promoter, the in silico studies and the significantly increased incidence of the S-S haplotype in hypospadiac patients raise the hypothesis of a particular susceptibility conferred by these variants.

Growth hormone and treatment outcomes: expert review of current clinical practice

Although there are guidelines for treatment of short stature, open questions regarding optimal management of growth hormone therapy still exist. Experts attending six international meetings agree that successful therapy results in the patient attaining mid-parental height, and relies on correct diagnosis and early intervention. Experts advocate patient followup every 3-6 months, and that growth and adherence should be monitored at each visit. Growth response is variable, and an accepted definition of good/poor response is lacking. Combined with patient education and regular patient follow-up, a definition of treatment response could lead to improved treatment outcomes. Few experts use prediction models in clinical practice, but all agree that pharmacogenetics might improve prediction, enable early therapy modulation, and promote growth. Poor growth is often due to low adherence. Guidance on optimal management of growth hormone therapy is required, with focus on early diagnosis, dosing, treatment monitoring, adherence, and motivation.

Heavy prenatal alcohol exposure and risk of stillbirth and preterm delivery

We prospectively identified 96 women consuming at least 4 drinks/day during pregnancy by screening 9628 pregnant women. In these women with heavy prenatal alcohol use, there were three stillbirths and one preterm delivery; 98 matched nondrinking women had no stillbirths and two preterm births. Preterm rates did not differ significantly. The stillbirth rate was higher in the exposed group (p = 0.06). Additional investigation showed the stillbirth rate in the exposed population (3.1%) was significantly higher (p = 0.019) than the reported Chilean population rate (0.45%). Our data suggest that heavy alcohol consumption may increase the risk for stillbirth but not preterm delivery.

Effects of prenatal ethanol exposure on postnatal growth and the insulin-like growth factor axis

AIMS

To study the effect of in-utero alcohol exposure on the insulin-like growth factor axis (IGF) and leptin during infancy and childhood, considering that exposed children may exhibit pre- and postnatal growth retardation.

METHODS

We prospectively identified heavily drinking pregnant women who consumed on average 4 or more drinks of ethanol per day (≥ 48 g/day) and assessed growth in 69 of their offspring and an unexposed control group of 83 children, measuring serum IGF-I (radioimmunoassay), IGF-II (immunoradiometric assay, IRMA), insulin-like growth factor-binding protein 3 (IGFBP-3) (IRMA) and leptin (IRMA) at 1 month and 1, 2, 3, 4, and 5 years of age.

RESULTS

IGF-II levels increased with age in both groups, but the rate of increase was significantly higher in exposed children, and levels were significantly higher in ethanol-exposed children at 3, 4, and 5 years of age. In exposed children, IGF-I levels were higher at 3 and 4 years and leptin levels were significantly lower at 1 and 2 years. Exposed subjects showed a much lower correlation between IGF-I and growth parameters than unexposed subjects.

CONCLUSION

Exposure to ethanol during pregnancy increases IGF-I and IGF-II and decreases leptin during early childhood. The increase in serum IGF-II concentrations in ethanol-exposed children suggests that this hormone should be explored as a potential marker for prenatal alcohol exposure.

Ghrelin plasma levels in patients with idiopathic short stature

BACKGROUND

Novel molecular insights have suggested that ghrelin may be involved in the pathogenesis of some forms of short stature. Recently, growth hormone secretagogue receptor (GHSR) mutations that segregate with short stature have been reported.

AIM

To study plasma ghrelin levels in prepubertal patients with idiopathic short stature (ISS).

METHODS

Fasting total plasma ghrelin levels (radioimmunoassay) in 41 prepubertal patients with ISS (18 females, age 7.9 ± 0.5 years) compared with 42 age- and sex-matched controls (27 females, age 8.0 ± 0.3 years) with normal height. In a subset of 28 patients, the ghrelin receptor was sequenced.

RESULTS

ISS patients exhibited a higher level of ghrelin (1,458 ± 137 vs. 935 ± 55 pg/ml, p < 0.01) and similar IGF-I levels (-0.66 ± 1.29 vs. -0.32 ± 0.78 SDS) compared to controls. Ten patients with ISS had ghrelin levels greater than +2 SDS compared to controls. These patients did not differ in height, BMI or IGF-I SDS compared to ISS patients with ghrelin levels within the normal range. Molecular analysis of GHSR did not show any mutations, but showed some polymorphisms.

CONCLUSION

These results suggest that in ISS patients, short stature does not appear to be frequently caused by abnormalities in ghrelin signaling.

Bone mass and sex steroids in postmenarcheal adolescents and adult women with Type 1 diabetes mellitus

OBJECTIVE

The aim of this study was to compare the bone mass in young adolescents and adult women with Type 1 diabetes mellitus (T1DM) and determine its relationship with sex steroid and sex hormone-binding globulin (SHBG) levels.

DESIGN

Cross-sectional study.

PATIENTS

We studied a group of adolescents and adult women with T1DM (n=45) and 50 healthy controls (C) matched by gynecological age and body mass index in a case-control study. Girls with menarche within the last 18-40 months (n=17 T1DM and 32 C) and adult women (age=30.4+1.4 years; n=28 T1DM and 18 C) were recruited.

MEASUREMENTS

Bone mass was evaluated with a GE Lunar Prodigy densitometer. Sex steroid levels were measured by radioimmunoassay.

RESULTS

Bone mass was lower in adolescents with T1DM than in control adolescents, but was similar in both groups of postmenarcheal girls after adjusting for age, lean, and fat mass. However, adult T1DM women exhibited lower adjusted and unadjusted (P<.05) Z-femoral neck (-0.2±0.2 vs. 0.4±0.2) and bone mineral content (BMC) (2306±61 vs. 2645±79 g) than adult controls. Adult controls and T1DM adults showed higher whole body BMC than adolescent controls and T1DM adolescents, respectively. Bone mass in T1DM did not correlate with estradiol, free estradiol, testosterone, SHBG, or HbA1c levels.

CONCLUSIONS

The diminished bone mass observed in adult T1DM women does not appear to be related to sex steroid levels. In young adolescents with T1DM, the observed decrease in bone mass appears to be related to differences in body composition and age.

Ovarian function in adolescents with McCune-Albright syndrome

OBJECTIVE

To evaluate ovarian function, especially ovulation rate, in adolescents with McCune-Albright syndrome (MAS) and a history of peripheral precocious puberty.

DESIGN

Prospective cross-sectional study.

SETTING

Academic center.

PATIENT(S)

A total of eight adolescents with MAS were compared with 15 healthy adolescents matched by age, Tanner stage and body mass index.

INTERVENTION(S)

We determined basal gonadotropins, sex steroids, sex hormone binding globulin, anti-Müllerian hormone, glucose and insulin. A leuprolide acetate test was performed to measure luteinizing hormone (LH) and follicle stimulating hormone (FSH) (at 0 and 3 h), and 17B-estradiol, testosterone and 17-OH-progesterone (at 0 and 24 h). Salivary progesterone levels were used to assess ovulation during the 13th, 18th, 23rd and 28th days of each menstrual cycle for three to five consecutive cycles, and one pelvic ultrasound was performed during the follicular phase.

MAIN OUTCOME MEASURE(S)

Ovulation rate in adolescents with MAS.

RESULT(S)

The proportion of ovulatory cycles was 52.6% in controls compared with 35.7% in patients with MAS.

CONCLUSION(S)

The adolescent girls with MAS appear to have a lower ovulatory rate compared with controls.

Acid-labile subunit (ALS) gene expression and protein content in human placentas: differences according to birth weight

CONTEXT

In humans, IGF-I and -II have an important role in pre- and postnatal growth. The IGFs circulate in plasma principally as a ternary complex with the IGF binding protein-3 and an acid-labile subunit (ALS), which increases their half life.

OBJECTIVES

The objectives of the study were to determine whether the human placenta expresses the mRNA and protein for ALS and to evaluate any possible differences in the mRNA and protein for ALS in placentas from small (SGA) and appropriate (AGA) or gestational age newborns.

SUBJECTS/METHODS

We studied the placentas from 47 AGA and 42 SGA pregnancies. IGF-I, IGF-II, IGF binding protein-3, and ALS placental mRNA and protein contents were determined in both the basal and the chorionic plates of the placenta.

RESULTS

We observed that the human placenta expresses the gene and protein for ALS. The ALS mRNA in SGA was higher compared with AGA placentas (0.15 ± 0.01 vs. 0.12 ± 0.01 arbitrary units, respectively, P < 0.05). In addition, the ALS protein content in SGA (31.7 ± 3.3 pmol/g) was higher compared with AGA (22.1 ± 2.3 pmol/g, P < 0.05) placentas.

CONCLUSION

We describe that the human placenta expresses the mRNA and the protein for ALS, and we observed an increase in ALS mRNA expression and protein content in SGA compared with AGA placentas.

Polycystic ovarian morphology in postmenarchal adolescents

OBJECTIVE

To evaluate the association of polycystic ovary morphology (PCOM) with ovarian function in adolescents and to determine its time course during two years of follow-up.

DESIGN

Prospective study.

SETTING

Academic center.

PATIENT(S)

Twenty healthy adolescents were followed from 2-4 years after menarche.

INTERVENTION(S)

We performed annual ultrasonographic and hormonal studies. Ovulation was assessed during 6 consecutive months by measuring salivary progesterone levels.

MAIN OUTCOME MEASURE(S)

Persistence of PCOM during the years following menarche; ovulation in girls with PCOM.

RESULT(S)

PCOM was observed in 40%, 35%, and 33.3% of the ultrasonographic studies performed at 2, 3, and 4 years after menarche, respectively. The concordance between ultrasonographic diagnosis at 2 and 4 years postmenarche (50%) was nonsignificant (kappa = 0.08). PCOM was not associated with abnormalities in ovulatory rate, menstrual cycle duration, lipid levels, or homeostatic model assessment of insulin resistance. However, lower FSH (4.8 ± 1.3 vs. 6.1 ± 1.9 mUI/ml) were observed in girls with PCOM compared with those without PCOM. Similar T and stimulated 17-hydroxyprogesterone on the leuprolide test were observed in girls with and without PCOM.

CONCLUSION(S)

PCOM is an inconstant finding in healthy adolescents and does not appear to be associated with decreased ovulatory rate or metabolic abnormalities in healthy adolescents. This finding suggests that PCOM may correspond to a physiologic condition during early adolescence.

Expression and protein content of IGF-I and IGF-I receptor in placentas from small, adequate and large for gestational age newborns

In humans, a direct relationship between IGF-I cord blood levels and birth weight has been demonstrated. To determine the placental IGF-I, IGF-II and IGF-IR mRNA and protein contents in full-term pregnancies from appropriate for gestational age (AGA), small for gestational age (SGA) and large for gestational age (LGA) newborns, we studied the placentas from 35 AGA, 30 SGA and 28 LGA pregnancies. The IGF-I, IGF-II and IGF-I receptor (IGF-IR) placental mRNA and protein contents were determined in the basal and chorionic plates of the placenta. IGF1 and IGF1R mRNA was higher in SGA compared to AGA and LGA placentas and lower in LGA compared with AGA placentas. In addition, a higher protein content of IGF-I and IGF-IR was observed in SGA compared with AGA and LGA placentas and lower contents in LGA compared with AGA placentas. These results suggest that the higher IGF-I and IGF-IR contents observed in SGA placentas and the lower contents observed in LGA placentas compared with AGA placentas may be influencing human fetal growth.

Cytoplasmic and nuclear STAT3 in GH-stimulated fibroblasts of children with idiopathic short stature

BACKGROUND

STAT5, which plays an important role in GH signal transduction, has been studied extensively in children with growth retardation, but there is scarce information regarding STAT3.

AIM

We determined total and phosphorylated STAT3 after GH stimulation in fibroblasts from children with idiopathic short stature (ISS) and control children with normal stature.

SUBJECTS AND METHODS

We studied 15 prepubertal children (age 7.6 ± 0.4 years) with short stature (height -2.8 ± 0.2 SDS), decreased growth velocity (10 ng/ml to the clonidine stimulation test and decreased serum IGF-I concentrations (<-1 SDS), and 19 control children with normal stature (age 6.7 ± 0.3 years). We determined the levels of total and phosphorylated STAT3 in the cytoplasmic and nuclear fractions of fibroblast cultures obtained from a skin biopsy, stimulated with GH (200 ng/ml) for 15-60 min.

RESULTS

We observed a reduction in nuclear pSTAT3 levels and a lower nuclear/cytoplasmic STAT3 phosphorylated ratio in 3 patients from the study group compared to the control children.

CONCLUSION

These results suggest that some children with ISS may exhibit a reduction in the nuclear content of their phosphorylated STAT3.

Effects of birth weight on anti-mullerian hormone serum concentrations in infant girls

CONTEXT

We previously demonstrated that low birth weight (BW) infant girls show increased serum anti-Müllerian hormone (AMH) concentrations and poststimulated estradiol levels compared to normal-BW infants, suggesting an altered follicular development. However, the impact of high BW on reproductive function is less known.

OBJECTIVE

To evaluate the effect of BW on AMH, we determined the concentrations of this hormone in low-BW, normal-BW, and high-BW female infants during the first 3 months of life.

DESIGN

Twenty-seven low-BW, 29 normal-BW, and 28 high-BW infant girls were studied. We measured serum gonadotropins, steroid hormones, AMH, glucose, insulin, free fatty acids, IGF-I, and adiponectin in a fasting blood sample. In addition, in a subgroup of normal-BW (n = 23) and high-BW infants (n = 10), a GnRH analog leuprolide acetate test was performed.

RESULTS

Serum concentrations of AMH were higher in low-BW and high-BW infants compared to normal-BW infants (P = 0.028 and 0.022, respectively). In addition, in high-BW infants, adiponectin concentrations were lower (P = 0.018), and poststimulated FSH and estradiol levels were higher compared to normal-BW infants (P = 0.024 and 0.047, respectively).

CONCLUSIONS

Serum AMH and poststimulated estradiol concentrations are increased in low-BW and high-BW female infants, suggesting that these girls may show evidence of an altered follicular development. However, the increased poststimulated FSH levels and low adiponectin concentrations observed in high-BW infants suggest that ovarian function is perturbed through a different mechanism from that in low-BW infants.

IGF-IR/ERK content and response to IGF-I and insulin in adipocytes from small for gestational age children

BACKGROUND/AIMS

The GH-IGF-I axis plays an important role on pre/postnatal growth in humans, and IGF-I regulates cell proliferation, differentiation, and metabolic homeostasis. The adipose tissue has an important function in energy storage, and plays an endocrine role through the production of several hormones and growth factors. There are few studies in humans regarding IGF-I and Insulin receptor signaling in adipocytes, particularly from AGA and SGA children.

METHODS

We studied 22 healthy prepubertal children (6.1+/-0.4 years), born at term (11 SGA and 11 AGA), and normal BMI at the time of the study. Primary cell cultures were established from subcutaneous adipose tissue biopsies. Preadipocytes were differentiated and stimulated with IGF-I or insulin and we studied IGF-IR, IR, AKT, and ERK content and phosphorylation.

RESULTS

The SGA children were shorter than the AGA children (height SDS -2.14+/-0.11 vs. 0.02+/-0.19, p<0.05). A lower content of IGF-IR, IR, AKT, and ERK was observed in adipocytes from SGA compared with AGA children. IGF-I stimulation increased IGF-IR and ERK phosphorylation in adipocytes from AGA, but not from SGA children.

CONCLUSION

The lower content and reduced phosphorylation of IGF-I signaling observed in adipocytes from SGA children may be related to the metabolic abnormalities described in these children.