RESUMO
Cryptorchidism is one of the most common congenital disorders in boys, and several genetic, hormonal, and environmental factors have been proposed as possible causes for this genitourinary defect. Genetic factors have been intensively searched, but relatively few pathogenic variants have been described. Cryptorchidism is a frequent finding in patients with RASopathies, a group of syndrome caused by mutations in genes of the Ras/MAPK pathway. Our aim was to determine whether patients with isolated cryptorchidism (IC) exhibit Ras/MAPK pathway gene variants associated with RASopathies. Two hundred thirty-nine patients with IC were recruited after orchidopexy. Determination of Ras/MAPK pathway gene variants was performed by high-resolution melting (HRM) analysis followed by sequencing. Restriction or allele-specific amplification assay was applied to (i) variant confirmation; (ii) search in healthy controls; and (iii) segregation analysis. Controls correspond to 100 healthy Chilean adults without a history of cryptorchidism. Molecular analysis showed one synonymous substitution (BRAF_p.Q456Q) in two patients and four missense substitutions (SOS1_ p.R497Q, BRAF_ p.F595L, NRAS_ p.T50I, and MAP2K2_ p.Y134C) in five patients. Our results suggest that some patients with isolated cryptorchidism, but with no evidence of dysmorphic features suggestive of RASopathies, may harbor Ras/MAPK pathway gene alterations.
Assuntos
Criptorquidismo/genética , GTP Fosfo-Hidrolases/genética , MAP Quinase Quinase 2/genética , Proteínas de Membrana/genética , Proteínas Proto-Oncogênicas B-raf/genética , Proteína SOS1/genética , Adolescente , Criança , Pré-Escolar , Chile , Variação Genética , Humanos , Lactente , Masculino , Proteínas Quinases Ativadas por Mitógeno/genética , Transdução de Sinais/fisiologia , Proteínas ras/genéticaRESUMO
Cryptorchidism is the most common congenital disorder in boys, but the cause for most cases remains unknown. Patients with Noonan Syndrome are characterized by a typical face, growth retardation, congenital heart defects, learning disabilities and cryptorchidism. Copy number variations of Ras/MAPK pathway genes are unusual in patients with several clinical features of Noonan Syndrome; however, they have not been studied in patients with only one feature of this condition, such as cryptorchidism. Our aim was to determine whether patients with isolated cryptorchidism exhibit Ras/MAPK pathway gene copy number variations (CNVs). Fifty-nine patients with isolated cryptorchidism and negative for mutations in genes associated with Noonan Syndrome were recruited. Determination of Ras/MAPK pathway gene CNVs was performed by Comparative Genome Hybridization array. A CNV was identified in two individuals, a ~175 kb microduplication at 3p25.2, partially including RAF1. A similar RAF1 microduplication has been observed in a patient with testicular aplasia. This suggests that some patients with isolated cryptorchidism may harbor Ras/MAPK pathway gene CNVs.
Assuntos
Criptorquidismo/genética , Dosagem de Genes , Sistema de Sinalização das MAP Quinases/genética , Adolescente , Criança , Pré-Escolar , Hibridização Genômica Comparativa , Duplicação Gênica , Genes ras , Humanos , Lactente , Masculino , Linhagem , Testosterona/sangueRESUMO
STUDY QUESTION: Are copy number variations (CNVs) in the pseudoautosomal regions (PARs) frequent in subjects with Y-chromosome microdeletions and can they lead to abnormal stature and/or neuropsychiatric disorders? SUMMARY ANSWER: Only subjects diagnosed with azoospermia factor (AZF)b+c deletions spanning to the end of the Y chromosome (i.e. terminal deletions) harbor Y isochromosomes and/or cells 45,X that lead to pseudoautosomal gene CNVs, which were associated with abnormal stature and/or neuropsychiatric disorders. WHAT IS KNOWN ALREADY: The microdeletions in the long arm of the Y chromosome (Yq) that include the loss of one to three AZF regions, referred to as Yq microdeletions, constitute the most important known etiological factor for primary spermatogenic failure. Recently, controversy has arisen about whether Yq microdeletions are associated with gain or loss of PAR genes, which are implicated in skeletal development and neuropsychiatric function. STUDY DESIGN, SIZE, DURATION: We studied a cohort of 42 Chilean patients with complete AZF deletions (4 AZFa, 4 AZFb, 23 AZFc, 11 AZFb+c) from a university medical center, diagnosed over a period of 15 years. The subjects underwent complete medical examinations with special attention to their stature and neuropsychiatric function. PARTICIPANTS/MATERIALS, SETTING, METHODS: All subjects were characterized for Yq breakpoints by PCR, and for CNVs in PARs by multiplex ligation-dependent probe amplification (MLPA), followed by qPCR analysis for genes in PAR1 (SHOX and ZBED1), PAR2 (IL9R) and two single copy genes (SRY and DDX3Y, respectively located in Yp11.3 and AZFa). In addition, karyotypes revision and fluorescence in situ hybridization (FISH) for SRY and centromeric probes for X (DXZ1) and Y (DYZ3) chromosomes were performed in males affected with CNVs. MAIN RESULTS AND THE ROLE OF CHANCE: We did not detect CNVs in any of the 35 AZF-deleted men with interstitial deletions (AZFa, AZFb, AZFc or AZFb+c). However, six of the seven patients with terminal AZFb+c deletions showed CNVs: two patients showed a loss and four patients showed a gain of PAR1 genes, with the expected loss of VAMP-7 in PAR2. In these patients, the Yq breakpoints localized to the palindromes P8, P5 or P4. In the four cases with gain of PAR1, qPCR analysis showed duplicated signals for SRY and DDX3Y and one copy of IL9R, indicating isodicentric Yp chromosomes [idic(Y)] with breakpoint in Yq11.22. The two patients who had loss of PAR1, as shown by MLPA, had an additional reduction for SRY and DDX3Y, as shown by qPCR, associated with a high proportion of 45,X cells, as determined by FISH and karyotype. In agreement with the karyotype analysis, we detected DYZ3++ and DYZ3+ cells by FISH in the six patients, confirming idic(Y) and revealing additional monocentric Y chromosome [i(Y)]. Five patients had a history of major depressive disorders or bipolar disorder, and three had language impairment, whereas two patients showed severe short stature (Z score: -2.75 and -2.62), while a man with bipolar disorder was very tall (Z score: +2.56). LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: The number of males studied with Y-chromosome microdeletions and normozoospermic controls with normal karyotypes may not be enough to rule out an association between AZF deletions and PAR abnormalities. The prevalence of Y isochromosomes and/or 45,X cells detected in peripheral blood does not necessarily reflect the variations of PAR genes in target tissues. WIDER IMPLICATIONS OF THE FINDINGS: This study shows that CNVs in PARs were present exclusively in patients with terminal AZFb+c deletions associated with the presence of Y isochromosomes and 45,X cells, and may lead to neuropsychiatric and growth disorders. In contrast, we show that men with interstitial Yq microdeletions with normal karyotypes do not have an increased risk of PAR abnormalities and of phenotypical consequences. Moreover, our results highlight the importance of performing molecular studies, which are not considered in the usual screening for patients with Yq microdeletions. STUDY FUNDING/COMPETING INTERESTS: This work was supported by the National Fund for Scientific and Technological Development of Chile (FONDECYT), grant no. 1120176 (A.C.). The authors declare that no conflicting interests exist.
Assuntos
Cromossomos Humanos Y , Transtornos do Crescimento/psicologia , Isocromossomos , Transtornos Mentais/genética , Oligospermia/genética , Regiões Pseudoautossômicas/genética , Adolescente , Adulto , Estatura/genética , Deleção Cromossômica , Variações do Número de Cópias de DNA , Humanos , Masculino , Adulto JovemRESUMO
AIMS: To evaluate C-reactive protein, insulin growth factor 1 and lipid levels during the follicular and luteal phases in adolescents with Type 1 diabetes. METHODS: Adolescents with Type 1 diabetes (N = 40) and healthy controls (C; N = 43) were studied during the follicular and luteal phases of their menstrual cycles. C-Reactive protein, insulin growth factor 1 and lipid levels were measured. RESULTS: Adolescents with Type 1 diabetes exhibited higher C-reactive protein levels than the C group during the follicular (P < 0.0001) and luteal phases (P < 0.01). The elevation of C-reactive protein levels was more pronounced in overweight adolescents with Type 1 diabetes than in adolescents in the C group. More adolescents with Type 1 diabetes were classified as having an elevated risk of cardiovascular disease (C-reactive protein > 3 mg/l) in the luteal phase than in the follicular phase (37.5% and 17.5%, respectively); half of the overweight adolescents with Type 1 diabetes in the luteal phase reached this level. BMI was the only significant factor affecting follicular and luteal phase C-reactive protein levels in adolescents with Type 1 diabetes. Lower insulin growth factor 1 levels were observed during both phases of the menstrual cycle in adolescents with Type 1 diabetes compared with controls. An elevation in insulin growth factor 1 levels in the luteal phase relative to the follicular phase was observed in controls, but not in adolescents with Type 1 diabetes. Luteal insulin growth factor 1 and C-reactive protein exhibited an inverse correlation (r = -0.4, P = 0.01). CONCLUSIONS: Adolescents with Type 1 diabetes have higher C-reactive protein levels and lower insulin growth factor 1 levels relative to controls, especially during the luteal phase. Type 1 diabetes diminishes the natural elevation in insulin growth factor 1 levels observed during the luteal phase in controls. Excess weight exacerbates the subclinical inflammatory state observed during both phases of the menstrual cycle in adolescents with Type 1 diabetes.
Assuntos
Proteína C-Reativa/análise , Diabetes Mellitus Tipo 1/sangue , Fase Folicular/sangue , Hiperlipidemias/complicações , Fator de Crescimento Insulin-Like I/análise , Fase Luteal/sangue , Sobrepeso/complicações , Adolescente , Biomarcadores/sangue , Índice de Massa Corporal , Doenças Cardiovasculares/complicações , Doenças Cardiovasculares/epidemiologia , Chile/epidemiologia , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/imunologia , Angiopatias Diabéticas/epidemiologia , Cardiomiopatias Diabéticas/epidemiologia , Regulação para Baixo , Feminino , Hospitais Públicos , Hospitais Urbanos , Humanos , Hiperlipidemias/epidemiologia , Lipídeos/sangue , Risco , Regulação para CimaRESUMO
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.
Assuntos
Recém-Nascido Pequeno para a Idade Gestacional/sangue , Fator de Crescimento Insulin-Like I/biossíntese , Placenta/metabolismo , Receptor IGF Tipo 1/biossíntese , Peso ao Nascer , Feminino , Humanos , Recém-Nascido , Fator de Crescimento Insulin-Like II/biossíntese , Gravidez , RNA Mensageiro/metabolismoRESUMO
Somatotrophic deficiency (SDMT) can be due to a deficiency of growth hormone releasing hormone(GHRH), growth hormone (GH) or insulin like growth factor I (IGF-I). Although its clinical features have been thoroughly described, the diagnosis is still controversial. Now there is an effective treatment with GH or IGF-I for these patients. AIM: To analyze the main clinical, etiological and laboratory characteristics of 75 SD patients (44 males), aged 9.4 + 4.5 years, with severe growth retardation. The diagnosis was confirmed by the lack of response to two GH stimulation tests (Clonidine, Glugagon or Insulin) and low levels of IGF-I or insulin-like growth factor binding protein- 3 (IGFBP-3). RESULTS: In 34 patients (46 percent), the cause of DSMT was considered idiopathic (DSMT-I), in 31 (41 percent) there was an organic cause (DSMT-O), most commonly caused by malformations or pituitary tumors and in 10 (13 percent), it was genetic (DSMT-G) (three patients with Laron's Syndrome, five with mutations of GH gene and 2 with probable mutations of Prop-1 and Pit-1 genes). IGF-1 levels, were significantly lower in DSMT-O and DSMT-G thanin DSMT-I (21.2 +/- 46.1, 23.4 +/-30.3 ng/mL and 50.2 +/- 48.3 ng/mL, respectively). The lowest height score corresponded to DSMT-G, compared to DSMT-O and DSMT (5.7 +/- 0.9, -4.0 +/- 1.6 and 4.3 +/- 1.2 DS, respectively) CONCLUSIONS: The high percentage of organic and genetic etiologies in our patients can be due to the systematic search of these diseases. DSMT-G (Laron, mutations in GH and Pit-1 genes) had the most severe growth retardation.
Assuntos
Humanos , Masculino , Feminino , Lactente , Pré-Escolar , Criança , Adolescente , Adulto , Estatura , Hormônio do Crescimento/deficiência , Transtornos do Crescimento/diagnóstico , Transtornos do Crescimento/etiologia , Antropometria , Chile , Nanismo/etiologia , Estudos Retrospectivos , Fator de Crescimento Insulin-Like I/análise , Hormônio do Crescimento/análise , Hormônio do Crescimento/genética , Mutação , Peso Corporal , /análise , Transtornos do Crescimento/genéticaRESUMO
We hypothesized that some children with idiopathic short stature in Chile might bear heterozygous mutations of the GH receptor. We selected 26 patients (3 females, 23 males) from 112 patients who consulted for idiopathic short stature at the University of Chile. Their chronological age was 8.3 +/- 1.9, and bone age was 6.1 +/- 1.0 yr. Their height was -3.0 +/- 0.7 SDS; IGF-I, -1.2 +/- 1.1 SD; IGF binding protein 3, -0.7 +/- 2.0 SDS; and GH binding protein, 0.4 +/- 0.8 SDS. Patients were admitted, and blood samples were obtained every 20 min to determine GH concentrations overnight. Coding sequences and intron-exon boundaries of exons 2-10 of GH receptor gene were amplified by PCR and subsequently analyzed through single-strand conformational analysis. Mean serum GH concentration, over 12-h, was 0.20 +/- 0.08 nM; pulse amplitude, 0.40 +/- 0.15 nM; number of peaks, 5.8 +/-1.5 peaks/12 h; peak value of GH during the 12-h sampling, 1.03 +/- 0.53 nM; and area under the curve, 151.4 +/- 56.1 nM/12 h. There were positive correlations between mean GH vs. area under the curve (P < 0.001) and GH peak (P < 0.01). The single-strand conformational analysis of the GH receptor gene showed abnormal migration for exon 6 in 9 patients and for exon 10 in 9 patients, which (by sequence analysis) corresponded to 2 polymorphisms of the GH receptor gene: an A-to-G transition in third position of codon 168 in exon 6 and a C-to-A transversion in the first position of codon 526 in exon 10. We further sequenced all coding exons and intron-exon boundaries in the most affected patients (nos. 6, 9, 11, 14, 15, 16, and 23). This analysis revealed a C-to-T transition in codon 161 of exon 6 in patient 23, which results in an amino acid change (Arg to Cys) in an heterozygous form in the patient and his father. In conclusion, the results of our study suggest that, in Chilean patients with idiopathic short stature, GH receptor gene mutations are uncommon, although we cannot exclude mutations that were missed by single-strand conformational analysis or mutations within introns or in the promoter regions of the GH receptor gene.
Assuntos
Estatura/genética , Transtornos do Crescimento/genética , Hormônio do Crescimento Humano/genética , Hormônio do Crescimento Humano/fisiologia , Autorradiografia , Sequência de Bases , Criança , Pré-Escolar , Chile , Primers do DNA , Éxons/genética , Feminino , Heterozigoto , Homozigoto , Humanos , Masculino , Biologia Molecular , Mutação/genética , Linhagem , Radioimunoensaio , Receptores da Somatotropina/genética , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Ibutamoren mesylate (MK-0677), an orally active nonpeptide growth hormone (GH) secretagogue, stimulates GH release through a pituitary and hypothalamic receptor that is different from the GH-releasing hormone receptor. We evaluated the safety and tolerability and the GH-insulin-like growth factor (IGF) responses to two dosages of oral ibutamoren mesylate given to children with GH deficiency for 7 to 8 days. The patients, 18 prepubertal children (15 male, 3 female) with idiopathic GH deficiency, had a chronologic age of 10.6 +/- 0.8 years (mean +/- SD), bone age of 7.4 +/- 0.7 years, growth velocity < 10th percentile for age, height < 10th percentile for age, and a maximum GH response of < or = 10 microg/L to two different GH stimulation tests. The children were assigned as follows to one of three treatment groups with ibutamoren mesylate: 0.2 mg/kg per day for 7 days (days 1-7 or 8-14) and matching placebo for the alternate 7 days (groups I and II, respectively) or 0.8 mg/kg per day for 7 days (days 8-14, group III). On day 15 all patients received an 0.8-mg/kg dose of ibutamoren mesylate. Patients in groups I and II were studied first to assess safety at the low dose before advancement to the high dose. Hormonal profiles were evaluated on day -1 (baseline) and day 15, and the results were expressed as the change from baseline within each group. After administration of ibutamoren mesylate 0.8 mg/kg for 8 days (group III), the median increases (on day 15) from baseline were as follows: 3.8 microg/L (range, 0 to 34.3) for serum GH peak concentration (P = .001), 4.3 microg x h/L (range, 1.3 to 35.6) for the GH area under the concentration-time curve from time zero to 8 hours (AUC(0-8)) (P < .001), 12 microg/L (range, -4 to 116) for serum IGF-I (P = .01), and 0.4 microg/L (range, -0.9 to 1.5) for serum IGF-binding protein 3 (IGFBP-3) (P = .01). There was no change in serum prolactin, glucose, triiodothyronine, thyroxine, thyrotropin, peak serum cortisol, and insulin concentrations or 24-hour urinary free cortisol after administration of 0.8 mg/kg per day of ibutamoren mesylate for 8 days. We conclude that short-term administration of ibutamoren mesylate can increase GH, IGF-I, and IGFBP-3 levels in some children with GH deficiency. Thus this compound is applicable for testing its effect on growth velocity.
Assuntos
Hormônio do Crescimento/efeitos dos fármacos , Hormônio do Crescimento/deficiência , Indóis/administração & dosagem , Indóis/farmacologia , Fator de Crescimento Insulin-Like I/efeitos dos fármacos , Erros Inatos do Metabolismo/tratamento farmacológico , Compostos de Espiro/administração & dosagem , Compostos de Espiro/farmacologia , Administração Oral , Criança , Método Duplo-Cego , Feminino , Humanos , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/efeitos dos fármacos , Fator de Crescimento Insulin-Like I/metabolismo , Masculino , Erros Inatos do Metabolismo/metabolismo , Resultado do TratamentoRESUMO
UNLABELLED: Circulating concentrations of the high affinity growth hormone binding protein (GHBP) may be a marker of GH receptor density as well as GH sensitivity. GOAL: To determine values of GHBP for a normal Chilean pediatric population. METHODS: We determined GHBP levels in 73 males and 73 females between 4 to 15.5 years and 4 to 16.8 years respectively, divided in 7 groups according to age and puberal status. RESULTS: The population was normally distributed in weight, height and body mass index (BMI). GHBP activity increased up to Tanner IV in males and Tanner III in females, and decreased slightly thereafter in Tanner V and IV respectively. There was a significant difference between GHBP levels of preschool children and those found in Tanner II to V in both sexes (p < 0.05). In addition, we found a positive correlation between GHBP vs weight, height and BMI (p < 0.001) in males and females. CONCLUSION: The availability of this methodology allows us to establish the normative value of GHBP in our population and provides useful information to interpret GH circulating levels in children with growth disorders.
Assuntos
Proteínas de Transporte/sangue , Adolescente , Biomarcadores/sangue , Estatura , Índice de Massa Corporal , Peso Corporal , Proteínas de Transporte/metabolismo , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Valores de ReferênciaRESUMO
Recently, several groups have studied the influence of possible noxious elements present in the intrauterine environment which may favor the development of several diseases in the adult. There is evidence of an increased prevalence of some disorders in special risk groups of fetuses. In the small for gestational age patient, a form of "programming" may occur which produce metabolic changes in the fetus in response to malnutrition. There are several other associations described, but in most of them the precise pathogenic mechanisms involved have not been elucidated. In this article we present evidence of several disorders which develop in the adult and their relationship with conditions during fetal life. Finally, we offer some recommendations to diminish these risks.