Η αυξητική ορμόνη (GH) παίζει ιδιαίτερα σημαντικό ρόλο, καθώς προάγει κυρίως τη μεταγεννητική κατά μήκος αύξηση, και ελέγχει το μεταβολισμό των λιπιδίων και των υδατανθράκων, τη σύνθεση των πρωτεϊνών και τη διέγερση του ανοσοποιητικού συστήματος. Η ανεπάρκεια GH (GHD) διαγιγνώσκεται είτε με παθολογικές συγκεντρώσεις της GH στον ορό μετά από πρόκληση με φαρμακολογικούς παράγοντες που διεγείρουν την έκκριση της (κλασσική GHD), είτε με φυσιολογικές προκλητές δοκιμασίες αλλά παθολογικό 24ωρο εκκριτικό ρυθμό της GH (GH νευροεκκριτική δυσλειτουργία, GHND). Οι GHD και GHND ασθενείς έχουν σοβαρή καθυστέρηση αύξησης και ανταποκρίνονται καλά στην εξωγενή θεραπεία με hGH. Κοντό ανάστημα που σχετίζεται με ανεπάρκεια αυξητικής ορμόνης (GHD) μπορεί να είναι σποραδικού τύπου και ιδιοπαθής, αλλά στο 5-30% των περιπτώσεων υπάρχει προσβεβλημένος πρώτου βαθμού συγγενής, που υποδηλώνει γενετική αιτιολογία. Μεταλλάξεις του γονιδίου της GH (GH1) ευθύνονται για την εκδήλωση οικογενούς μεμονωμένης ανεπάρκειας GH (IGHD). Ο εγγύς υποκινητής του GH1 γονιδίου παρουσιάζει υψηλού βαθμού πολυμορφισμό, με τουλάχιστον 16 αναγνωρισμένους πολυμορφισμούς (SNPs) σε έκταση 535 βάσεων, που εκδηλώνονται σε σύνολο 40 απλότυπων, κάποιοι από τους οποίους επηρεάζουν την έκφραση της GH. Σκοπός της παρούσας εργασίας ήταν η ανεύρεση αλλαγών στην αλληλουχία του GH1 γονιδίου της αυξητικής ορμόνης (GH) και του εγγύς υποκινητή του σε ασθενείς με οικογενή μεμονωμένη ανεπάρκεια GH (IGHD), αλλά και η ανάλυση του τρόπου κληρονομικότητας αυτών των αλλαγών. Μελετήθηκαν 33 IGHD ασθενείς (29 GHD και 4 GHND), τα μέλη των οικογενειών τους (22 οικογένειες) και 31 μάρτυρες. Απομονώθηκε γονιδιωματικό DNA από λεμφοκύτταρα περιφερικού αίματος και πραγματοποιήθηκε πολλαπλασιασμός του GH1 γονιδίου και του υποκινητή του με την αλυσιδωτή αντίδραση πολυμεράσης (PCR). Τα δείγματα αλληλουχήθηκαν και προσδιορίστηκαν αλλαγές της αλληλουχίας με βάση την NCBI, blast- Μ28466.1-βάση δεδομένων. Στους ασθενείς μετρήθηκαν τα επίπεδα IGF-1, τα επίπεδα των άλλων ορμονών του πρόσθιου λοβού του αδένα της υπόφυσης, η μέγιστη τιμή GH μετά από προκλητές δοκιμασίες με κλονιδίνη και L-Dopa, και στους 4 GHND ασθενείς πραγματοποιήθηκε 24ωρη καταγραφή της αυθόρμητης έκκρισης της GH. Οι πολυμορφισμοί (SNPs) που ανιχνεύθηκαν στο GH1 γονίδιο και τον υποκινητή του σε ασθενείς και μάρτυρες, ελέγχθηκαν για τη συχνότητα των γονοτύπων τους, και συσχετίστηκαν με κλινικοεργαστηριακά χαρακτηριστικά, ενώ ο δυνητικός λειτουργικός ρόλος των μεταλλάξεων ελέγχθηκε με λογισμικά προγράμματα. Η αλληλούχιση του GH1 γονιδίου και του υποκινητή του ανέδειξε 18 γνωστούς από τη βιβλιογραφία SNPs στον υπό μελέτη πληθυσμό και τρεις νέες (novel) μεταλλάξεις στις 3 από τις 22 οικογένειες. Ανάλυση με το λογισμικό πρόγραμμα MatΙinspector των 2 ετερόζυγων σημειακών μεταλλάξεων που εντοπίστηκαν στον GH1 υποκινητή, -485G>C and -400G>A, αποκάλυψε θέση πρόσδεσης για τον μεταγραφικό παράγοντα E-twenty six-1 (ETS-1). Ανάλυση της τρίτης ετερόζυγης μετάλλαξης (G>A) στη θέση +300 του εσωνίου 1 του GH1 γονιδίου με τα λογισμικά ESEfinder3 και ASSP αποκάλυψε τη δημιουργία μιας κρυφής θέση ματίσματος και διάσπαση της περιοχής ματίσματος εξωνίου (ESE) ενός ψευδοεξωνίου, μειώνοντας τον αριθμό προσδενόμενων πρωτεϊνών πλούσιων σε σερίνη-αργινίνη (SR). Η στατιστική ανάλυση των συχνοτήτων των γονοτύπων στους πολυμορφισμούς υψηλής συχνότητας, και η συσχέτιση τους με παραμέτρους που σχετίζονται με την αύξηση, την έκκριση της GH, αλλά και την ανταπόκριση στην hGH αγωγή, έδειξε ότι οι GHD ασθενείς πιθανόν να εμφανίζουν διαφορετική μεταγραφική δραστηριότητα στο GH1 γονίδιο λόγω των θέσεων -278, -57 του υποκινητή, -6 της 5΄ UTR περιοχής και της θέσης +1169 του γονιδίου, που έρχεται σύμφωνο και με άλλες μελέτες, αλλά και της θέσης -31, που αναφέρεται για πρώτη φορά. Αυτοί οι πολυμορφισμοί συσχετίστηκαν με μειωμένα επίπεδα IGF-1. Από την άλλη, οι SNPs που αναγνωρίσθηκαν στους GHND ασθενείς, παρόλο που είναι παρόμοιοι με αυτούς των GHD ασθενών, συσχετίστηκαν με παραμέτρους αύξησης και όχι με τα επίπεδα IGF-1. Οι 18 πολυμορφισμοί και οι 3 μεταλλάξεις που εντοπίστηκαν στους GHD και GHND ασθενείς φαίνεται να συμβάλουν μερικώς και μεμονωμένα ή συνεργικά στη μεταγραφή του GH1 γονιδίου και συνεπώς στην έκκριση της GH, ενώ η διαφορετική συμμετοχή των SNPs στους GHD και GHND ασθενείς πιθανόν αντανακλά και τη διαφορετική εκδήλωση της νόσου. Η κατανόηση της φαινοτυπικής ποικιλότητας των ασθενών με IGHD και των γενετικών αιτιών μπορεί να βοηθήσει στη κατανόηση των μηχανισμών που ενέχονται στον έλεγχο της αύξησης, αλλά και στη βελτίωση της παρακολούθησης και της θεραπείας των ασθενών. / Growth hormone (GH) plays a pivotal role in a number of physiological processes by promoting postnatal longitudinal body growth, lipid and carbohydrate metabolism, protein biosynthesis and activation of the immune system. GH deficiency (GHD) is diagnosed either by subnormal levels of serum GH during two hGH stimulation tests by pharmacological agents that physiologically stimulate GH secretion (classic form of GHD), or normal serum GH levels, but subnormal 24hr GH profile (Neurosecretory GH deficiency, GHND). Children with GHD and GHND have severe growth retardation and respond to exogenous human GH (hGH) therapy with significant catch-up growth. Short stature associated with isolated GH deficiency (GHD) is both sporadic and idiopathic, but between 5 and 30% have an affected first degree relative consistent with a genetic etiology. Mutations identified on the GH gene (GH1) associate with the manifestation of familial isolated GH deficiency (IGHD). The proximal promoter region of GH1 exerts a highly polymorphic region, with at least 16 single nucleotide polymorphisms (SNPs) identified over a region of 535bp, manifested by a total of 40 haplotypes, some of which affect the GH1 expression. The aim of this study was to identify possible changes in the sequence of the GH1 gene of growth hormone (GH) and its promoter region in patients with familial isolated GH deficiency (IGHD), together with the analysis of the inheritance pattern of such genetic changes. 33 IGHD patients (29 GHD and 4 GHND), their 1st degree relatives (22 families) and 31 controls were investigated. Genomic DNA was extracted from the lymphocytes of the subjects peripheral blood and the GH1 gene was amplified by the Polymerase Chain Reaction (PCR). The samples were sequenced and the changes were identified according to the sequence M28466.1 of the NCBI blast database. The levels of IGF-1 and other hormones of the pituitary were measured in the patients and the highest level of GH during the clonidine and L-Dopa hGH stimulation test were recorded, whereas in the 4 GHND patients a spontaneous 24hr GH profile was conducted. The sequencing results were analyzed for the frequencies of the genotypes of the identified SNPs and for any possible correlations with the clinical or biochemical characteristics of the patients and the controls. Additionally, the possible functional role of the found mutations was assessed using specific programs. The sequencing of GH1 and its promoter revealed 18 SNPs in the whole sample and 3 novel mutations in 3 of the 22 investigated families. Analysis with MatInspector of the 2 heterozygous nucleotide mutations located at the promoter regions -485GC and -400GA, respectively, revealed a binding sequence for the transcription factor E-twenty six-1 (ETS-1). Analysis of the third heterozygous mutation (GA) at the +300 region of intron 1 with ESEfinder3 και ASSP revealed a cryptic splicing position and disruption of the exon splicing enhancement (ESE) region by reducing the binding affinity of serine-arginine proteins (SRs). The frequency and correlation analysis showed that the GHD patients possible exert differential transcriptional activity at the GH1 gene via the SNPs at positions -278, -57 of the promoter, -6 of 5΄ UTR region, +1169 of intron 4, which is in accordance to previous studies, and also the newly reported SNP at -31 region. These SNPs associated also with decreased IGF-1 levels. On the other hand, the SNPs identified in the GHND patients, although similar to the GHD patients, correlated with several growth parameters, irrespective to the IGF-1 levels. The 18 SNPs and 3 mutations identified in the sample seem to contribute partially and individually or in synergy to the transcriptional regulation of GH1 in the GHD and GHND patients. The SNPs contribution is differentially exerted in the GHD patients, when compared to the GHND patients and this possibly reflects the different expression of the disease. The investigation of phenotypic variance in IGHD patients and their genetic predisposition can potentially improve our perception of the underlying mechanisms of growth and offer valuable information for the better therapeutic management of IGHD patients.

IGF-I, the circulating effector of growth hormone (GH) action, is essential for differentiation and survival of neurons and maturation of inner ear cells. Isolated GH deficiency (IGHD) represents an ideal model to study the impact of GH/IGF-I axis on hearing. In Itabaianinha County, Northeast Brazil, it had been described the most extend kindred with severe IGHD due to a GH-releasing hormone receptor gene homozygous mutation. (GHRHR). The aim of this transversal study was to evaluate hearing IGHD subjects. 26 IGHD dwarfs individuals (13 females) and 25 controls (15 females) matched by sex and age were studied. They were submitted to a questionnaire on hearing complaints and hearing health history and hearing tests like audiometry, logoaudiometry, acoustic immitance and stapedial reflex. To assess the outer hair cell function in the cochlea, transient evoked otoacoustic emissions (TEOAEs) were done. To assess the auditory nerve and auditory brainstem, auditory brainstem evoked responses (ABR) were obtained. Variables with normal and not normal distribution were compared in the two groups by t test and Mann-Whitney test, respectively. Misophonia and dizziness were more frequent in IGHD than controls (p=0.011). IGHD subjects presented higher thresholds in 250 Hz (p=0.005), 500 Hz (p=0.006), 3 kHz (p=0.008), 4 kHz (p=0.038), 6 kHz (p=0.008) and 8 KHz (p=0.048), and mild high-tones hearing loss (p=0.029).Stapedial reflex (p<0.001) and TEOAEs (p<0.001) were more frequent in controls. There were no statistic differences in ABRs latencies between groups. Hearing loss in IGHD occurred earlier than controls. Conclusions: subjects with untreated, congenital lifetime IGHD report more misophonia and dizziness, have predominance of mild high-tones sensorineural hearing loss, absence of stapedial reflex and of TEOAEs when compared to normal controls from the same area. Hearing loss in IGHD occurred earlier than controls. These data suggest an effect of the GH-IGF-I axis on hearing function and hearing aging. / O principal efetor circulante do hormônio do crescimento (GH), Insulin-like growth factor I (IGF-I), é essencial para a diferenciação, sobrevivência e maturação dos neurônios das células do orelha interna. A deficiência isolada do hormônio do crescimento (DIGH) representa um modelo ideal para estudar o impacto do eixo GH/IGF-I na audição. Na cidade de Itabaianinha-SE, foi descrito o maior agrupamento familiar com DIGH severa devido a uma mutação homozigótica no gene do receptor do hormônio liberador do hormônio do crescimento (GHRHR). O objetivo deste estudo transversal foi avaliar a audição em indivíduos com DIGH. 26 indivíduos com DIGH (13 mulheres) e 25 indivíduos controles (15 mulheres) pareados por sexo e idade, foram estudados. Eles foram submetidos a um questionário sobre queixas auditivas e história pregressa por entrevista e testes auditivos como audiometria tonal, logoaudiometria, imitanciometria e reflexo acústico estapediano. Para acessar a função das células ciliadas externas da cóclea, foram utilizadas as emissões otoacústicas evocadas transientes (EOAEvT). O potencial evocado auditivo de tronco encefálico (PEATE) foi utilizado para se avaliara atividade neural desde a cóclea até o tronco encefálico.. Para comparação entre os grupos foram utilizados os testes t para variáveis de distribuição normal e Mann-Whitney para variáveis de distribuição não normal O valor de p<0.05 foi considerado estatisticamente significante. As queixas de misofonia e tontura foram mais frequentes no grupo DIGH (p=0.011). 24 indivíduos DIGH realizaram a audiometria tonal com limiares mais altos nas frequências 250 Hz (p=0.005), 500 Hz (p=0.006), 3 kHz(p=0.008), 4 kHz (p=0.038), 6 kHz (p=0.008) e 8 kHz (p=0.048) e a maioria apresentou perda leve em agudos (p=0.024). A presença do reflexo acústico estapediano e das emissões otoacústicas transientes foi mais frequente no grupo controle (p<0.001). Não houve diferença estatística entre os grupos para as latências do PEATE e não houve alteração da morfologia das ondas em ambos os grupos. A perda auditiva ocorreu mais precoce no grupo DIGH. Conclusões: Os indivíduos com DIGH congênita, não tratada, relatam mais misofonia e tontura, têm predominância de perda auditiva neurossensorial leve em agudos, ausência de reflexo acústico estapediano e EOAEvT quando comparados com o grupo controle da mesma área. A perda auditiva neurossensorial ocorreu em idade mais precoce no grupo DIGH do que no controle. Esses dados sugerem os efeitos do eixo GH-IGF-I na função auditiva e no envelhecimento da audição.

GH and its principal mediator IGF-I have important effects on metabolic and cardiovascular (CV) status. While acquired GH deficiency (GHD) is often associated to increased CV risk, the consequences of congenital GHD are not known. We have described a large group of patients with isolated GHD (IGHD) due to a homozygous mutation (c.57+1G>A) in the GH releasing hormone receptor gene, and shown that adult GH-naïve individuals have no evidence of clinically evident premature atherosclerosis. To test weather subclinical atherosclerosis is anticipated in untreated IGHD, we ruled a cross-sectional study of 25 IGHD and27 adult controls matched for age and gender. A comprehensive clinical and biochemical panel and coronary artery calcium scores by multi-detector tomography were evaluated. Height, weight, IGF-I, homeostasis model assessment of insulin resistance, creatinine and creatinokinase were lower in IGHD group. Median and interquartile range of calcium scores distribution was similar in the two groups: IGHD 0 (0) and control 0 (4.9). The vast majority of the calcium scores [20 of 25 IGHD (80%) and 18 of 27 controls (66.6%)] were equal to zero (difference not significant). There was no difference in the calcium scores classification. None of IGHD subjects had minimal calcification, which were present in 4 controls. Three IGHD and four controls had mild calcification. There were two IGHD individuals with moderate calcification and one control with severe calcification. Our study provides evidence that subjects with congenital isolated lifetime and untreated severe IGHD do not have accelerated subclinical coronary atherosclerosis. / O GH e seu principal mediador IGF-I têm importantes efeitos no perfil metabólico e cardiovascular (CV). Enquanto a deficiência adquirida do hormônio do crescimento (DGH) está frequentemente associada ao aumento no risco CV, as consequências da deficiência congênita não são conhecidas. Descrevemos um grande grupo de pacientes com deficiência isolada de hormônio do crescimento (DIGH) secundária a mutação homozigótica (c.57+1G>A) no gene do receptor do hormônio liberador do GH, e mostramos que indivíduos adultos depletados de GH não têm evidência de aterosclerose prematura clinicamente manifesta. Para testar se a aterosclerose subclínica se antecipa na DIGH não tratada, realizamos um estudo transversal com 25 portadores de DIGH e 27 controles adultos pareados por sexo e idade. Características clínicas e bioquímicas e escore de cálcio (EC) coronário pela tomografia computadorizada por múltiplos detectores, foram avaliados. Altura, peso, IGF-I, modelo de homeostase de avaliação da resistência a insulina (HOMAIR), creatinina e creatinoquinase foram menores no grupo DIGH. Mediana e intervalo interquartis da distribuição do EC foram similares entre os dois grupos: DIGH 0(0) e controles 0 (4.9). A vasta maioria dos EC [20 de 25 DIGH (80%) e 18 de 27 controles (66.6%)] foi igual a zero (diferença não significativa). Não houve diferença na classificação de EC. Nenhum dos indivíduos portadores de DIGH apresentou calcificação mínima, a qual estava presente em 4 controles. Três portadores de DIGH e 4 controles tinham calcificação leve. Dois portadores de DIGH com moderada calcificação e 1 controle com calcificação severa. Nosso estudo fornece evidências de que indivíduos com DIGH congênita, isolada, vitalícia e não tratada não têm aterosclerose coronariana subclínica precoce.

Background: Growth hormone (GH) has been used to treat children with GH deficiency (GHD) since 1966. Aims: Using a combined retrospective and cross-sectional approach, we explored the long-term outcomes of patients with GHD, analysed factors influencing therapeutic response, determined persistence into adulthood, investigated pituitary morphology, and screened for mutations in causative genes. Methods: The files of 96 GH-deficient children were reviewed. In a subset of 50 patients, re-assessment in adulthood was performed, including GHRH-arginine testing, pituitary magnetic resonance imaging (MRI), and mutational screening for the growth hormone-1 gene (GH1) and the GHRH receptor gene (GHRHR) in isolated GHD (IGHD), and HESX1 , PROP1 , POU1F1 , LHX3 , LHX4 , and GLI2 in multiple pituitary hormone deficiency (MPHD) patients. Results: GH was started at a height SDS of –3.2 ± 1.4 in IGHD patients and of –4.1 ± 2.1 in MPHD patients. Relative height gain was 0.3 SDS/year, absolute gain 1.6 SDS, and 1.2/2.6 SDS in IGHD/MPHD, respectively. Mid-parental target height was reached in 77%. Initial height SDS, bone age retardation and duration of GH replacement were correlated with height SDS gain. GHD persisted into adulthood in 19 and 89% of subjects with IGHD and MPHD, respectively. In 1/42 IGHD patients a GH1 mutation was detected; PROP1 mutations were found in 3/7 MPHD subjects. Anterior pituitary hypoplasia, combined with posterior pituitary ectopy and pituitary stalk invisibility on MRI, was an exclusive finding in MPHD patients. Conclusions: GH replacement successfully corrects the growth deficit in children with GHD. While the genetic aetiology remains undefined in most cases of IGHD, PROP1 mutations constitute a major cause for MPHD. Persistence of GHD into adulthood is related to abnormal pituitary morphology.