PROP1 Mutations Research Articles

Prolactin deficiency in the context of other pituitary hormone abnormalities : Special issue: hypoprolactinemia: a neglected endocrine disorder.

Prolactin deficiency is rare. It generally occurs when pituitary disorders, such as large pituitary tumors, pituitary apoplexy, and other conditions associated with sellar mass effect lead to global failure of pituitary function and hypopituitarism. In these situiations, prolactin is commonly the last pituitary hormone affected, after growth hormone and gonadotropins are lost and thyroid-stimulating hormone and adrenocorticotopic hormone secretion is impaired. Prolactin deficiency accompanies several congenital syndromes due to mutations in PROP1 and Pit1/ POU1F and in X-linked IGSF1 deficiency syndrome, and several aqcuired conditions including Sheehan syndrome, IgG4-related hypophysitis, and immune checkpoint-inhibitor-induced hypophysitis. In women, prolactin deficiency prevents lactation following childbirth among other symptoms associated with hypopituitarism. Human prolactin is not available commercially as replacement therapy. However, recombinant human prolactin administered daily to women with hypoprolactinemia and alactogenesis was found to lead to the production of significant milk volume sufficient for lactation.

Pituitary stalk interruption syndrome (PSIS) in a newborn with PROP1 mutation

Pituitary stalk interruption syndrome (PSIS) in a newborn with PROP1 mutation

Familial Combined Pituitary Hormone Deficiency by a Mutation in PROP1 – a Case Report

Objective This paper aimed to emphasize the importance of considering the diagnosis of PROP1 mutation in all cases where multiple members of the same family are affected by combined pituitary hormone deficiencies (CPHD).Case Report − We describe two brothers of unrelated parents with a mutation in the PROP1 gene. Both brothers presented with growth impairment - the older one at the age of 2.5 years, and the younger one at the age of 3.3 years. Central hypothyroidism and GH deficiency were established in both of them. Replacement therapy was started using levothyroxine and recombinant growth hormone. Pituitary magnetic resonance imaging was normal. Genetic analysis identified a pathogenic homozygous frameshift variant c.301_302delAG in the PROP1 gene.Conclusion − Patients with PROP1 mutation must be closely followed up to reveal other possible hormonal defects and to avoid possible life-threatening adrenal crisis in the future. PROP1 mutation should be considered in all familial forms of CPHD and in all patients who have a deficiency of two or more pituitary hormones.

Assessment of adrenal axis function in patients with PROP1 mutation - longitudinal observation

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Association of Homozygous PROP1 Mutation in a Saudi Family with Combined Pituitary Hormone Deficiency

Background and Objectives: Combined pituitary hormone deficiency (CPHD) is a rare heterogeneous disease. It is characterized by the deficiency of growth hormone (GH) and shortage of at least one or more other hormones of the pituitary gland including thyroid-stimulating hormone (TSH), luteinizing hormone (LH), follicle-stimulating hormone (FSH), and prolactin. Rare pathogenic variants in nearly 30 genes have been identified as an underlying cause of CPHD pathogenicity. Among these genes, paired-like homeobox 1 (PROP1) has been reported to be the most common cause of CPHD. Materials and Methods: In the present study, we investigated a large family of Saudi origin with three adult sisters suffering from short stature in combination of secondary amenorrhea. Results: Whole-exome sequencing followed by Sanger sequencing shows a homozygous missense variant (NM_006261.5; c.211C > T; p.R71C) in the PROP1 gene segregating with the disease phenotype within the family. In silico analysis studies show that this variant is highly conserved among several orthologues and is predicted as likely pathogenic using various bioinformatics tools. Conclusions: Our finding presents the first Saudi familial case of autosomal recessive form of CPHD caused by the PROP1 variant.

OR17-4 Hormone Replacement Promotes Sexual Maturation and Fertility Restoration in Mice With Congenital Hypopituitarism Harboring Prop1 Mutation

Abstract Introduction The Ames strain, a spontaneous mutant mouse of the Prop1 gene, is deficient in GH, TSH, PRL and gonadotropins. In recent years, it has been the focus of studies on aging and there is a growing interest in elucidating the role of hormone replacement (HR) in the hypothalamic-pituitary-gonadal (HPG) axis. Aim The present study aimed to characterize sexual maturation and fertility restoration in isogenic strain under or not HR. Material and methods Five homozygous male animals were treated via intraperitoneal injections, starting 30 days postnatally, with levothyroxine 3x/week and recombinant human GH 5x/week for 40 days, followed by maintenance applications of both hormones once a week until they complete 90 days post natal. The sexual maturity was evaluated looking for balanoprepucial opening and descendent testis comparing untreated homozygous (n=5) with their wild type siblings (n=5). Fertility was evaluated by mating known fertile wild type animals with treated and untreated animals for 8 times. Reproductive parameters were evaluated between groups using histological sections of the testes (HE) and classified according to johnsen score where 1-2 was classified as absent germline cells and 8-10 normal development. At the sacrifice, testicular weight was measured using scale and spermogram was done looking for motility and viability in the sperm collected in the seminiferous tube. Gata2 transcription factor and pituitary hormones Lh, Fsh, Tsh, Prl and Gh transcriptional analysis were performed by RT-qPCR. Results The homozygous treated animals presented a 2 weeks delay in the age of sexual maturation compared to wild animals. Their fertility and reproductive parameters were restored noticed by increased testicular weight, improved spermatogenesis, similar morphology of seminiferous tubules (johnsen score 8.7) and spermogram compared to the wild type, besides presenting offspring when mated to their wild siblings. Sexual maturity was absent in most of the untreated homozygous animals presenting no offspring. The reproductive parameters in the untreated homozygous animals presented reduced testicular weight, size of seminiferous tubes leading to johnsen score as 5 and an azospermic spermogram in all animals. Interestingly 2 untreated homozugous animal had spontaneous maturation. Gata2 was significant decreased in the untreated animal (0,49 ± 0,19) compared to wild type (1 ± 0,15) (p≤ 0.019). LH transcriptional pattern was significant increase in the animals under treatment (1.56 ± 0.68) compared to homozygotes without hormonal intervention (0.36 ± 0.34) (p≤ 0.048). Conclusion Ames mutant mice under treatment with GH and levothyroxine replacement reached sexual maturation and restored fertility and the mechanics behind this phenomenon will be explored using RNA seq in the future. Presentation: Sunday, June 12, 2022 11:45 a.m. - 12:00 p.m.

Testing of Adrenal Axis Function in Patients With Combined Pituitary Hormone Deficiency Caused by PROP1 Mutation

Background: The mechanism of adrenal axis deterioration in PROP1 mutation remains uncertain and challenging. Aim: The aim of the project was to investigate the adrenal axis function in patients with combined pituitary function deficiency and PROP1 mutation. Methods: We performed the corticotrophin (CRH) stimulation test in 15 patients ((8W/7M) with confirmed CPHD due to the PROP1 mutation. 9/15 were familial cases from four families. Time of observation (ToO) was calculated since the first pituitary axis/ACTH insufficiency has occurred. The results were reported in the group with confirmed Adrenal Insufficiency (AI) and without AI defined as cortisol >18 ug/dl at any point during CRH test. ACTH is reported in pg/ml and cortisol in ug/dl, time of test is given in minutes (0‘, 15’,30’,45’,60’,120’). Results: The mean age of the group was 40,6 ± 12,1 years with mean 34,7 ± 10,3 years of CPHD observation (range 18 – 54 years). The In 5/15 the cortisol response met the criteria excluding AI. Among siblings there were patients both with/without AI. Both subgroups had similar ToO (without AI 35,6 ± 10,0 years vs 34,2 ± 10,3 years with AI). Mean time of AI duration was 15,0 ± 9,3 years. In the group of 5 patients without AI the mean morning cortisol was 12,48 ± 4,31 and ACTH was 31,26 ± 5,43. The mean maximal concentration of cortisol and ACTH were 24,94 ± 3,6 and 123,6 ± 39,9 respectively; Mean increase of cortisol was 12,46 ±4,04 and 92,34±34,48 for ACTH. In 10 patients with AI the mean morning cortisol was 3,33±1,39 and ACTH 22,71±6,75. The mean maximal concentration of cortisol and ACTH were 10,15±4,47 and 97,05 ± 59,15 respectively; Mean increase of cortisol was 6,83 ± 3,41 and 74,35 ± 53,72 for ACTH. For two patients high ACTH increase from 36,7 to 260 and from 28,65 to 112,0 was observed. Analysis of cortisol and ACTH response in both groups revealed that in group without AI the time of peak of ACTH was observed in 15’ (2/5) and 30’ (3/5) vs. in 15’(3/10), 30’(6/10) and 45’ in group with AI. The peak cortisol was observed in 30’, 45’ and 60’ (3/5) in group without AI vs 60’(6/10) or 120’ (4/10) in AI group. The mean maximal increase of ACTH was by 4,09±1,46 and 4,12±1,58 in AI group vs no AI group respectively. Conclusions: In patients with PROP1 mutation the adrenal axis can deteriorate long after other axis insufficiencies, however there are patients with no adrenal insufficiency even during lifelong observation. There is no specific order of deterioration even among affected siblings. In the vast majority of patients independently of cortisol increase there is ACTH response after CRH. Further studies on the pituitary function deterioration in patients with PROP1 mutation should be carried out to understand better the underlying mechanism and to set up the diagnostic timing and procedures.

PROP-1 geninde homozigot delesyon mutasyonuna sahip iki kız kardeş

Defects in the PROP-1 gene produce clinical findings by affecting somatotrophs, thyrotrophs, lactotrophs, gonadotrophs and corticotrophs. The first finding in cases with PROP-1 gene mutation is growth retardation associated with growth hormone (GH) deficiency and central hypothyroidism. Other hormone deficiencies are added over time. We describe two sisters with deletion mutation in the PROP-1 gene. The parents were first-degree cousins. The female patient identified as the index case was 4.6 and the other sister was 1.9 years old when they presented with failure to thrive and short stature. Central hypothyroidism and GH deficiency was determined in both sisters. Homozygous deletion mutation was determined in the PROP-1 gene at genetic analysis. PROP-1 mutation should be considered in patients presenting with combined GH deficiency and central hypothyroidism, and the diagnosis must be confirmed with genetic analysis.

Clinical lessons learned in constitutional hypopituitarism from two decades of experience in a large international cohort.

The international GENHYPOPIT network collects phenotypical data and screens genetic causes of non-acquired hypopituitarism. To describe main phenotype patterns and their evolution through life. Patients were screened according to their phenotype for coding sequence variations in 8 genes: HESX1, LHX3, LHX4, PROP1, POU1F1, TBX19, OTX2 and PROKR2. Among 1213 patients (1143 index cases), the age of diagnosis of hypopituitarism was congenital (24%), in childhood (28%), at puberty (32%), in adulthood (7.2%) or not available (8.8%). Noteworthy, pituitary hormonal deficiencies kept on evolving during adulthood in 49 of patients. Growth Hormone deficiency (GHD) affected 85.8% of patients and was often the first diagnosed deficiency. AdrenoCorticoTropic Hormone deficiency rarely preceded GHD, but usually followed it by over 10years. Pituitary Magnetic Resonance Imaging (MRI) abnormalities were common (79.7%), with 39.4% pituitary stalk interruption syndrome (PSIS). The most frequently associated extrapituitary malformations were ophthalmological abnormalities (16.1%). Prevalence of identified mutations was 7.3% of index cases (84/1143) and 29.5% in familial cases (n=146). Genetic analysis in 449 patients without extrapituitary phenotype revealed 36 PROP1, 2 POU1F1 and 17 TBX19 mutations. This large international cohort highlights atypical phenotypic presentation of constitutional hypopituitarism, such as post pubertal presentation or adult progression of hormonal deficiencies. These results justify long-term follow-up, and the need for systematic evaluation of associated abnormalities. Genetic defects were rarely identified, mainly PROP1 mutations in pure endocrine phenotypes.

Genetic spectrum and predictors of mutations in four known genes in Asian Indian patients with growth hormone deficiency and orthotopic posterior pituitary: an emphasis on regional genetic diversity.

Regional variation in prevalence of genetic mutations in growth hormone deficiency (GHD) is known. Study phenotype and prevalence of mutations in GH1, GHRHR, POU1F1, PROP1 genes in GHD cohort. One hundred and two patients {Isolated GHD (IGHD): 79; combined pituitary hormone deficiency (CPHD): 23} with orthotopic posterior pituitary were included. Auxologic, hormonal and radiological details were studied. All four genes were analysed in IGHD patients. POU1F1 and PROP1 were studied in CPHD patients. Of 102, 19.6% were familial cases. Height SDS, mean (SD) was - 5.14 (1.63). Peak GH, median (range) was 0.47ng/ml (0-6.59), 72.5% patients had anterior pituitary hypoplasia (APH). Twenty mutations (novel: 11) were found in 43.1% patients (n = 44, IGHD-36, CPHD-8). GHRHR mutations (n = 32, p.Glu72* = 24) were more common than GH1 mutations (n = 4) in IGHD cohort. POU1F1 mutations (n = 6) were more common than PROP1 mutations (n = 2) in CPHD cohort. With few exceptions, this prevalence pattern is contrary to most studies in world-literature. No patients with peak GH > 4ng/ml had mutations, signifying it as negative predictor. While many parameters were significant on univariate analysis, only positive family history and lower median peak GH levels were significant predictors of mutations on multivariate analysis in IGHD patients. At variance with world literature, we found reverse predominance of GHRHR over GH1 mutations, POU1F1 over PROP1 mutations and predominance of GHRHR p.Glu72* mutations thus re-affirming the regional diversity in GHD genetics. We report positive and negative predictors of mutations in GHD.

Mutations Within the Transcription Factor PROP1 in a Cohort of Turkish Patients with Combined Pituitary Hormone Deficiency

Objective:Mutations of the genes encoding transcription factors which play important roles in pituitary morphogenesis, differentiation and maturation may lead to combined pituitary hormone deficiency (CPHD). PROP1 gene mutations are reported as the most frequent genetic aetiology of CHPD. The aim of this study was to describe the phenotypes of Turkish CPHD patients and define the frequency of PROP1 mutations.Methods:Fifty-seven CPHD patients from 50 families were screened for PROP1 mutations. The patients were affected by growth hormone (GH) and additional anterior pituitary hormone deficiencies.Results:All patients had GH deficiency. In addition, 98.2% had central hypothyroidism, 45.6% had hypogonadotropic hypogonadism, 43.8% had adrenocorticotropic hormone deficiency and 7.1% had prolactin deficiency. Parental consanguinity rate was 50.9% and 14 cases were familial. Mean height standard deviation score (SDS) and weight SDS were -3.8±1.4 and -3.1±2.0, respectively. Of 53 patients with available pituitary imaging, 32 (60.4%) showed abnormalities. None had extra-pituitary abnormalities. Eight index patients had PROP1 gene mutations. Five sporadic patients were homozygous for c.301_302delAG (p.Leu102CysfsTer8) mutation, two siblings had exon 2 deletion, two siblings had complete gene deletion and two siblings were homozygous for the novel c.353A>G (p.Q118R) mutation. The frequency of the PROP1 mutations was 16% in our cohort. Mutation rate was significantly higher in familial cases compared to sporadic cases (42.8% vs 11.6%; p<0.01).Conclusion:Phenotype of patients regarding hormonal deficiencies, pituitary morphology, presence of extra-pituitary findings, family history of CPHD and parental consanguinity are important for deciding which pituitary transcription factor deficiency should be investigated. PROP1 mutation frequencies vary in different populations and its prevalence is high in Turkish CPHD patients.

The time, mode and markers of pituitary function deterioration in patients with PROP1 mutation. Single centre, longitudinal observation

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Metabolic status of patients with combined pituitary hormone deficiency due to PROP1 mutation

Metabolic status of patients with combined pituitary hormone deficiency due to PROP1 mutation

Hypopituitarism in five PROP1 mutation siblings: long-lasting natural course and the effects of growth hormone replacement introduction in middle adulthood.

Twenty years after the first description of combined hypopituitarism (CPHD) caused by PROP1 mutations, the phenotype of affected subjects is still challenging for clinicians. These patients suffer from pituitary hormone deficits ranging from IGHD to panhypopituitarism. ACTH deficiency usually develops later in life. Pituitary size is variable. PROP1 mutation is the most frequent in familial congenital hypopituitarism (CH). Reports on initiation of hormonal replacement including growth hormone (GH) in adults with CH are scarce. We identified 5 adult siblings with CPHD due to PROP1 mutation (301-302delAG), aged 36-51years (4 females), never treated for hormone deficiencies. They presented with short stature (SD from - 3.7 to - 4.7), infantile sexual characteristic, moderate abdominal obesity and low bone mineral density in 3 of them. Complete hypopituituitarism was confirmed in three siblings, while two remaining demonstrated GH, TSH, FSH and LH deficiencies. Required hormonal replacement including rhGH was initiated in all patients. After several months necessity for hydrocortisone replacement developed in all patients. After 2 years of continual replacement therapy, BMD and body composition (measured by DXA-dual X-ray absorptiometry) improved in all subjects, most prominently in two younger females and the male sibling. Besides rhGH therapy, these three patients have received sex hormones contributing to the favorable effect. The male sibling was diagnosed with brain glioblastoma two years following complete hormonal replacement. This report provides important experience regarding hormonal replacement, particularly rhGH treatment, in adults with long-term untreated CH. Beneficial effect of such therapy are widely acknowledged, yet these subjects could be susceptible to certain risks of hormonal treatment initiated in adulthood. Careful and continual clinical follow-up is thus strongly advised.

Adrenal axis deterioration in the families/sporadic patients with PROP1 mutation, over 30 years of single center longitudinal observation

Adrenal axis deterioration in the families/sporadic patients with PROP1 mutation, over 30 years of single center longitudinal observation

OR24-2 PROP1 Directs Pituitary Differentiation through Protein Interaction and for Regulation of Gene Expression Involved in an EMT-Like Process

Multiple factors participate in the differentiation process of the pituitary. In particular, PROP1 is a member of the paired-like family of homeodomain transcription factors, is expressed early in Rathke’s pouch and is key in the developing pituitary. In humans, PROP1 mutations are the leading causes of Combined Pituitary Hormone Deficiency (CPHD). We previously have determined that Prop1 is essential for stimulating stem cells to undergo an epithelial to mesenchymal transition-like (EMT) process, but it is not well understood how Prop1 regulates this process. In this work, we explored the role of Prop1 in pituitary differentiation, and the proteins with which interacts to complete its functions. To this end, we genetically engineered the GHFT1 mouse pituitary cell line to express biotin-tagged Prop1. We used this cell line and its control counterpart, that does not express Prop1, to identify PROP1-mediated changes in gene expression by RNA-seq and Prop1-interacting proteins by mass spectrometry. Gene expression profiling revealed that Prop1 upregulates genes involved in the migration process, either dispersion or adhesion, and genes implicated in degrading extracellular matrix proteins, i.e. matrix metalloproteinases (MMP2, MMP15 and MMP19). On the other hand, Prop1 downregulates tissue inhibitor of metalloproteinases like TIMP-3. Specifically, MMPs play a crucial role in embryonic development and have been implicated in EMT in the morphogenesis of many tissues. We examined MMP2 protein expression by immunofluorescence during pituitary development in control and Prop1df/df mice. At e12.5, e14.5 and e16.5, MMP2 is normally expressed in the pituitary gland in normal mice and it is almost absent in Prop1 mutant pituitaries. Furthermore, we observed an increased in cell-cell junctions by TEM in P1 pituitaries from Prop1df/df mice. Using immunoprecipitation coupled to mass spectrometry, we identified 93 proteins that interact specifically with Prop1. These proteins were tested for GO biological process enrichment and two predominant terms were determined: cell-cell adherents’ junction and cell-cell adhesion. Several genes from these groups were previously described for their involvement in migration and EMT. Said genes fail in Prop1 mutants. Altogether, these results unveil the different actors in the Prop1 network, either by direct interaction with the transcription factor or by regulation of target gene expression. This knowledge could pinpoint candidate genes that could explain cases of hypopituitarism with unknown etiology and thereby, yield an improved diagnosis. And as a future perspective it could lead to the development of a targeted therapy that could overcome the disease.

Genetic variation in thyroid folliculogenesis influences susceptibility to hypothyroidism-induced hearing impairment.

Maternal and fetal sources of thyroid hormone are important for the development of many organ systems. Thyroid hormone deficiency causes variable intellectual disability and hearing impairment in mouse and man, but the basis for this variation is not clear. To explore this variation, we studied two thyroid hormone-deficient mouse mutants with mutations in pituitary-specific transcription factors, POU1F1 and PROP1, that render them unable to produce thyroid stimulating hormone. DW/J-Pou1f1dw/dw mice have profound deafness and both neurosensory and conductive hearing impairment, while DF/B-Prop1df/df mice have modest elevations in hearing thresholds consistent with developmental delay, eventually achieving normal hearing ability. The thyroid glands of Pou1f1 mutants are more severely affected than those of Prop1df/df mice, and they produce less thyroglobulin during the neonatal period critical for establishing hearing. We previously crossed DW/J-Pou1f1dw/+ and Cast/Ei mice and mapped a major locus on Chromosome 2 that protects against hypothyroidism-induced hearing impairment in Pou1f1dw/dw mice: modifier of dw hearing (Mdwh). Here we refine the location of Mdwh by genotyping 196 animals with 876 informative SNPs, and we conduct novel mapping with a DW/J-Pou1f1dw/+ and 129/P2 cross that reveals 129/P2 mice also have a protective Mdwh locus. Using DNA sequencing of DW/J and DF/B strains, we determined that the genes important for thyroid gland function within Mdwh vary in amino acid sequence between strains that are susceptible or resistant to hypothyroidism-induced hearing impairment. These results suggest that the variable effects of congenital hypothyroidism on the development of hearing ability are attributable to genetic variation in postnatal thyroid gland folliculogenesis and function.

Combined pituitary hormone deficiency caused by PROP1 mutations: update 20 years post-discovery.

The first description of patients with combined pituitary hormone deficiencies (CPHD) caused by PROP1 mutations was made 20 years ago. Here we updated the clinical and genetic characteristics of patients with PROP1 mutations and summarized the phenotypes of 14 patients with 7 different pathogenic PROP1 mutations followed at the Hospital das Clínicas of the University of Sao Paulo. In addition to deficiencies in GH, TSH, PRL and gonadotropins some patients develop late ACTH deficiency. Therefore, patients with PROP1 mutations require permanent surveillance. On magnetic resonance imaging, the pituitary stalk is normal, and the posterior lobe is in the normal position. The anterior lobe in patients with PROP1 mutations is usually hypoplastic but may be normal or even enlarged. Bi-allelic PROP1 mutations are currently the most frequently recognized genetic cause of CPHD worldwide. PROP1 defects occur more frequently among offspring of consanguineous parents and familial cases, but they also occur in sporadic cases, especially in countries in which the prevalence of PROP1 mutations is relatively high. We classified all reported PROP1 variants described to date according to the American College of Medical Genetics and Genomics and the Association for Molecular Pathology (ACMG-AMP) guidelines: 29 were pathogenic, 2 were likely pathogenic, and 2 were of unknown significance. An expansion of the phenotype of patients with PROP1 mutations was observed since the first description 20 years ago: variable anterior pituitary size, different pathogenic mutations, and late development of ACTH deficiency. PROP1 mutations are the most common cause of autosomal recessive CPHD with a topic posterior pituitary lobe. Arch Endocrinol Metab. 2019;63(2):167-74.

Screening a large pediatric cohort with GH deficiency for mutations in genes regulating pituitary development and GH secretion: Frequencies, phenotypes and growth outcomes.

Abstract Background Pituitary development and GH secretion are orchestrated by multiple genes including GH1, GHRHR, GLI2, HESX1, LHX3, LHX4, PROP1, POU1F1, and SOX3. We aimed to assess their mutation frequency and clinical relevance in children with severe GH deficiency (GHD). Methods The Genetics and Neuroendocrinology of Short Stature International Study (GeNeSIS; Clinical Trial Registry Number: NCT01088412 ) was a prospective, open-label, observational research program for pediatric patients receiving GH treatment, conducted in 30 countries between 1999 and 2015. The study included a sub-study to investigate mutations in the genes listed above. PCR products from genomic blood cell DNA were analyzed by Sanger sequencing. DNA variants were classified as pathogenic according to the recommendations of the American College of Medical Genetics and Genomics. Demographic, auxologic, and endocrine data at baseline and during GH treatment were documented and related to the genotyping results. Findings The analysis comprised 917 patients. In 92 patients (10%) 33 mutations were found, 16 previously described and 17 novel (52%). Mutation carriers were significantly younger, shorter, and more slowly growing than non-carriers. In general, their peak values in GH stimulation tests were very low; however, in 15/77 (20%) patients with GH1, PROP1, and SOX3 mutations they were only moderately diminished (3-6 μg/L). Two patients with a GH1 mutation developed TSH deficiency and one ADH deficiency. Using logistic multi-regression analysis, significant indicators of a mutation were combined pituitary hormone deficiency, greater patient-parent height difference (SDS), low GH peak, and young age. Final height SDS gain in mutation carriers (mean ± SD 3.4 ± 1.4) was greater than in non-carriers (2.0 ± 1.4; P Interpretation DNA testing for mutations in children with severe GHD shows a positive finding in approximately 10%. Phenotypes of mutation carriers can be variable. The benefit for clinical practice justifies DNA testing as an important component in the diagnostic work-up of patients with severe GHD. Fund Eli Lilly and Company, Indianapolis, IN, USA. ClinicalTrials.com registration: NCT01088412 .

Activation of Nrf2 in the liver is associated with stress resistance mediated by suppression of the growth hormone-regulated STAT5b transcription factor.

The transcription factor Nrf2 (encoded by Nfe2l2) induces expression of numerous detoxifying and antioxidant genes in response to oxidative stress. The cytoplasmic protein Keap1 interacts with and represses Nrf2 function. Computational approaches were developed to identify factors that modulate Nrf2 in a mouse liver gene expression compendium. Forty-eight Nrf2 biomarker genes were identified using profiles from the livers of mice in which Nrf2 was activated genetically in Keap1-null mice or chemically by a potent activator of Nrf2 signaling. The rank-based Running Fisher statistical test was used to determine the correlation between the Nrf2 biomarker genes and a test set of 81 profiles with known Nrf2 activation status demonstrating a balanced accuracy of 96%. For a large number of factors examined in the compendium, we found consistent relationships between activation of Nrf2 and feminization of the liver transcriptome through suppression of the male-specific growth hormone (GH)-regulated transcription factor STAT5b. The livers of female mice exhibited higher Nrf2 activation than male mice in untreated or chemical-treated conditions. In male mice, Nrf2 was activated by treatment with ethinyl estradiol, whereas in female mice, Nrf2 was suppressed by treatment with testosterone. Nrf2 was activated in 5 models of disrupted GH signaling containing mutations in Pit1, Prop1, Ghrh, Ghrhr, and Ghr. Out of 59 chemical treatments that activated Nrf2, 36 exhibited STAT5b suppression in the male liver. The Nrf2-STAT5b coupling was absent in in vitro comparisons of chemical treatments. Treatment of male and female mice with 11 chemicals that induce oxidative stress led to activation of Nrf2 to greater extents in females than males. The enhanced basal and inducible levels of Nrf2 activation in females relative to males provides a molecular explanation for the greater resistance often seen in females vs. males to age-dependent diseases and chemical-induced toxicity.