Hormone resistance and short stature: A journey through the pathways of hormone signaling.

Hormone resistances have been described in association with growth disorders, the majority involving the growth hormone (GH)/insulin-like growth factor 1(IGF-1) axis or hormones with specific paracrine-autocrine actions in the growth plate. Defects in hormone receptors or in proteins involved in intracellular signal transduction (post-receptor defects) are the main mechanisms of hormone resistance leading to short stature. The characteristic phenotypes of each of these hormonal resistances are very distinct and bring with them important insights into the role of each hormone and its signaling pathway. In this review, we discuss the molecular and clinical aspects of the main hormone resistances associated with short stature in humans.

Is There a Difference Between Minimal and Gross Extension into the Strap Muscles for the Risk of Recurrence in Papillary Thyroid Carcinomas?

Background: The morbidity of papillary thyroid carcinoma (PTC) is primarily related to locoregional recurrences and distant metastases. The definition of minimal extrathyroidal extension (mETE) has been recently revised. The presence of mETE does not impact mortality and is generally not considered to be a predictor for the risk of recurrence. This study aimed at comparing the risk of recurrence and the response to therapy of PTC with mETE and gross extrathyroidal extension (ETE) into the strap muscles (gETE) with low- and intermediate-risk PTC without ETE (low risk w/o ETE and intermediate risk w/o ETE, respectively) to further characterize the impact of ETE on outcomes. Methods: A total of 596 PTCs were analyzed according to the degree of ETE as well as other predictors of recurrence. Four groups of patients were compared, low risk w/o ETE (n = 251), intermediate risk w/o ETE (n = 89), mETE (n = 191), and gETE (n = 65), to determine the risk of recurrence and the response to treatment. Cox proportional hazards models were used to investigate associations between groups and disease-free survival (DFS). Results: The risk of recurrence was 3% in low risk w/o ETE PTC, 14% in intermediate risk w/o ETE, 14% in mETE, and 25% in gETE. The recurrence risk was increased by the presence of ETE (odds ratio [OR] = 2.86, 95% confidence interval [CI] 1.36-5.85, p = 0.005) and lymph node metastases (OR = 2.44 [95% CI 1.25-4.76], p = 0.009). Patients with low-risk carcinomas w/o ETE experienced longer DFS than those with mETE (hazard ratio = 0.08 [95% CI 0.02-0.28], p < 0.001), but no significant difference was observed between intermediate risk w/o ETE, mETE, and gETE. In terms of the response to therapy, patients with gETE had higher rates of biochemical and/or structural incomplete responses within the first year of treatment (OR = 2.68 [95% CI 1.31-5.45], p = 0.007) and at the final follow-up evaluation (OR = 4.35 [95% CI 1.99-9.51], p < 0.001) compared with those with mETE. An analysis of the subgroups of microcarcinomas without lymph node metastases revealed no significant difference in DFS or the response to therapy between the low risk w/o ETE and mETE PTC groups. Conclusions: The results of this study suggest that both mETE and gETE are independent risk factors for the risk of recurrence in PTC. Although gETE has a more pronounced impact on the recurrence risk and is associated with a worse response to therapy, mETE may not be associated with a low risk of recurrence. This observation suggests that patients with PTC and mETE may, in part, have an intermediate risk of recurrence and need to be followed accordingly.

Update on new GH-IGF axis genetic defects

ABSTRACT The somatotropic axis is the main hormonal regulator of growth. Growth hormone (GH), also known as somatotropin, and insulin-like growth factor 1 (IGF-1) are the key components of the somatotropic axis. This axis has been studied for a long time and the knowledge of how some molecules could promote or impair hormones production and action has been growing over the last decade. The enhancement of large-scale sequencing techniques has expanded the spectrum of known genes and several other candidate genes that could affect the GH-IGF1-bone pathway. To date, defects in more than forty genes were associated with an impairment of the somatotropic axis. These defects can affect from the secretion of GH to the bioavailability and action of IGF-1. Affected patients present a large heterogeneous group of conditions associated with growth retardation. In this review, we focus on the description of the GH-IGF axis genetic defects reported in the last decade. Arch Endocrinol Metab. 2019;63(6):608-17

Quality of Life and Coping in Multiple Endocrine Neoplasia Type 2.

Scarce data are available on the quality of life and psychosocial distress of patients with multiple endocrine neoplasia type 2 (MEN2), a genetic cancer syndrome caused by RET germline mutations. Carriers of RET mutations can face several challenges, including fear for the future, guilt for transmission of a germline mutation to an offspring, side effects of cancer treatment, coping behaviors in the face of a chronic and frequently incurable cancer, and difficulties in access to adequate health care. We have addressed the effects of genetic testing on the quality of life of patients with MEN2 and the lifelong physical and psychosocial challenges experienced by these patients. We have also suggested strategies to minimize the burden of living with this chronic condition and the perspectives on future studies to improve the health-related quality of life of the patients.

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.

Genetic diagnosis of congenital hypopituitarism by a target gene panel: novel pathogenic variants in GLI2, OTX2 and GHRHR.

AIM: Congenital hypopituitarism has an incidence of 1:3500-10,000 births and is defined by the impaired production of pituitary hormones. Early diagnosis has an impact on management and genetic counselling. The clinical and genetic heterogeneity of hypopituitarism poses difficulties to select the order of genes to analyse. The objective of our study is to screen hypopituitarism genes (candidate and previously related genes) simultaneously using a target gene panel in patients with congenital hypopituitarism. METHODS: Screening of 117 subjects with congenital hypopituitarism for pathogenic variants in 26 genes associated with congenital hypopituitarism by massively parallel sequencing using a customized target gene panel. RESULTS: We found three novel pathogenic variants in OTX2 c.295C>T:p.Gln99*, GLI2 c.1681G>T:p.Glu561* and GHRHR c.820_821insC:p.Asp274Alafs*113, and the previously reported variants in GHRHR c.57+1G>A and PROP1 [c.301_302delAG];[c.109+1G>A]. CONCLUSIONS: Our results indicate that a custom-designed panel is an efficient method to screen simultaneously variants of biological and clinical relevance for congenital GH deficiency. A genetic diagnosis was possible in 5 out of 117 (4%) patients of our cohort. We identified three novel pathogenic variants in GHRHR, OTX2 and GLI2 expanding the spectrum of variants associated with congenital hypopituitarism.

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

ABSTRACT 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

Update on new GH-IGF axis genetic defects.

The somatotropic axis is the main hormonal regulator of growth. Growth hormone (GH), also known as somatotropin, and insulin-like growth factor 1 (IGF-1) are the key components of the somatotropic axis. This axis has been studied for a long time and the knowledge of how some molecules could promote or impair hormones production and action has been growing over the last decade. The enhancement of large-scale sequencing techniques has expanded the spectrum of known genes and several other candidate genes that could affect the GH-IGF1-bone pathway. To date, defects in more than forty genes were associated with an impairment of the somatotropic axis. These defects can affect from the secretion of GH to the bioavailability and action of IGF-1. Affected patients present a large heterogeneous group of conditions associated with growth retardation. In this review, we focus on the description of the GH-IGF axis genetic defects reported in the last decade. Arch Endocrinol Metab. 2019;63(6):608-17.

Pathogenic copy number variants in patients with congenital hypopituitarism associated with complex phenotypes.

OBJECTIVES: The aetiology of congenital hypopituitarism (CH) is unknown in most patients. Rare copy number variants (CNVs) have been implicated as the cause of genetic syndromes with previously unknown aetiology. Our aim was to study the presence of CNVs and their pathogenicity in patients with idiopathic CH associated with complex phenotypes. DESIGN AND PATIENTS: We selected 39 patients with syndromic CH for array-based comparative genomic hybridization (aCGH). Patients with pathogenic CNVs were also evaluated by whole exome sequencing. RESULTS: Twenty rare CNVs were detected in 19 patients. Among the identified rare CNVs, six were classified as benign, eleven as variants of uncertain clinical significance (VUS) and four as pathogenic. The three patients with pathogenic CNVs had combined pituitary hormone deficiencies, and the associated complex phenotypes were intellectual disabilities: trichorhinophalangeal type I syndrome (TRPS1) and developmental delay/intellectual disability with cardiac malformation, respectively. Patient one has a de novo 1.6-Mb deletion located at chromosome 3q13.31q13.32, which overlaps with the region of the 3q13.31 deletion syndrome. Patient two has a 10.5-Mb de novo deletion at 8q23.1q24.11, encompassing the TRPS1 gene; his phenotype is compatible with TRPS1. Patient three carries a chromosome translocation t(2p24.3;4q35.1) resulting in two terminal alterations: a 2p25.3p24.3 duplication of 14.7 Mb and a 4-Mb deletion at 4q35.1q35.2. CONCLUSIONS: Copy number variants explained the phenotype in 8% of patients with hypopituitarism and additional complex phenotypes. This suggests that chromosomal alterations are an important contributor to syndromic hypopituitarism.

Successful Pregnancies After Adequate Hormonal Replacement in Patients With Combined Pituitary Hormone Deficiencies.

CONTEXT: Women with hypopituitarism have lower pregnancy rates after ovulation induction. Associated pituitary hormone deficiencies might play a role in this poorer outcome. OBJECTIVE: We evaluated fertility treatment and pregnancy outcomes in five women with childhood-onset combined pituitary hormone deficiencies (CPHD). PATIENTS AND METHODS: Five women with CPHD were referred for fertility treatment after adequacy of hormone replacement was determined. Patients were subjected to controlled ovarian stimulation (COS) for timed intercourse, intrauterine insemination, or in vitro fertilization, according to the presence or absence of other infertility factors (male or tubal). RESULTS: All women became pregnant. The number of COS attempts until pregnancy was achieved varied between 1 and 5. The duration of COS resulting in at least one dominant follicle varied between 9 and 28 days, and total gonadotropin consumed varied between 1200 and 3450 IU. Two patients with severely suppressed basal gonadotropin levels since an early age had a cancelled COS cycle. All pregnancies were singleton except one (monochorionic twin gestation). The gestational ages at birth ranged from 35 weeks to 39 weeks and 4 days; three patients underwent cesarean section, and two had vaginal deliveries. Only one newborn was small for gestational age (delivered at 35 weeks). CONCLUSION: Adequate hormonal replacement prior to ovarian stimulation resulted in successful pregnancies in patients with childhood-onset CPHD, indicating that hormone replacement, including growth hormone, is an important step prior to fertility treatments in these patients.

Growth hormone deficiency with advanced bone age: phenotypic interaction between GHRH receptor and CYP21A2 mutations diagnosed by sanger and whole exome sequencing

SUMMARY Isolated growth hormone deficiency (IGHD) is the most common pituitary hormone deficiency and, clinically, patients have delayed bone age. High sequence similarity between CYP21A2 gene and CYP21A1P pseudogene poses difficulties for exome sequencing interpretation. A 7.5 year-old boy born to second-degree cousins presented with severe short stature (height SDS −3.7) and bone age of 6 years. Clonidine and combined pituitary stimulation tests revealed GH deficiency. Pituitary MRI was normal. The patient was successfully treated with rGH. Surprisingly, at 10.8 years, his bone age had advanced to 13 years, but physical exam, LH and testosterone levels remained prepubertal. An ACTH stimulation test disclosed a non-classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency explaining the bone age advancement and, therefore, treatment with cortisone acetate was added. The genetic diagnosis of a homozygous mutation in GHRHR (p.Leu144His), a homozygous CYP21A2 mutation (p.Val282Leu) and CYP21A1P pseudogene duplication was established by Sanger sequencing, MLPA and whole-exome sequencing. We report the unusual clinical presentation of a patient born to consanguineous parents with two recessive endocrine diseases: non-classic congenital adrenal hyperplasia modifying the classical GH deficiency phenotype. We used a method of paired read mapping aided by neighbouring mis-matches to overcome the challenges of exome-sequencing in the presence of a pseudogene.

Molecular analysis of brazilian patients with combined pituitary hormone deficiency and orthotopic posterior pituitary lobe reveals eight different PROP1 alterations with three novel mutations.

BACKGROUND: Mutations in PROP1, HESX1 and LHX3 are associated with combined pituitary hormone deficiency (CPHD) and orthotopic posterior pituitary lobe (OPP). OBJECTIVE: To identify mutations in PROP1, HESX1 and LHX3 in a large cohort of patients with CPHD and OPP (35 Brazilian, two Argentinian). DESIGN AND METHODS: We studied 23 index patients with CPHD and OPP (six familial and 17 sporadic) as well as 14 relatives. PROP1 was sequenced by the Sanger method in all except one sporadic case studied using a candidate gene panel. Multiplex ligation-dependent probe amplification (MLPA) was applied to one familial case in whom PROP1 failed to amplify by PCR. In the 13 patients without PROP1 mutations, HESX1 and LHX3 were sequenced by the Sanger method. RESULTS: We identified PROP1 mutations in 10 index cases. Three mutations were novel: one affecting the initiation codon (c.1A>G) and two affecting splicing sites, c.109+1G>A and c.342+1G>C. The known mutations, c.150delA (p.Arg53Aspfs*112), c.218G>A (p.Arg73His), c.263T>C (p.Phe88Ser) and c.301_302delAG (p.Leu102Cysfs*8), were also detected. MLPA confirmed complete PROP1 deletion in one family. We did not identify HESX1 and LHX3 mutations by Sanger. CONCLUSION: PROP1 mutations are a prevalent cause of congenital CPHD with OPP, and therefore, PROP1 sequencing must be the first step of molecular investigation in patients with CPHD and OPP, especially in populations with a high frequency of PROP1 mutations. In the absence of mutations, massively parallel sequencing is a promising approach. The high prevalence and diversity of PROP1 mutations is associated with the ethnic background of this cohort.

Growth hormone deficiency with advanced bone age: phenotypic interaction between GHRH receptor and CYP21A2 mutations diagnosed by sanger and whole exome sequencing.

Isolated growth hormone deficiency (IGHD) is the most common pituitary hormone deficiency and, clinically, patients have delayed bone age. High sequence similarity between CYP21A2 gene and CYP21A1P pseudogene poses difficulties for exome sequencing interpretation. A 7.5 year-old boy born to second-degree cousins presented with severe short stature (height SDS -3.7) and bone age of 6 years. Clonidine and combined pituitary stimulation tests revealed GH deficiency. Pituitary MRI was normal. The patient was successfully treated with rGH. Surprisingly, at 10.8 years, his bone age had advanced to 13 years, but physical exam, LH and testosterone levels remained prepubertal. An ACTH stimulation test disclosed a non-classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency explaining the bone age advancement and, therefore, treatment with cortisone acetate was added. The genetic diagnosis of a homozygous mutation in GHRHR (p.Leu144His), a homozygous CYP21A2 mutation (p.Val282Leu) and CYP21A1P pseudogene duplication was established by Sanger sequencing, MLPA and whole-exome sequencing. We report the unusual clinical presentation of a patient born to consanguineous parents with two recessive endocrine diseases: non-classic congenital adrenal hyperplasia modifying the classical GH deficiency phenotype. We used a method of paired read mapping aided by neighbouring mis-matches to overcome the challenges of exome-sequencing in the presence of a pseudogene.

A homozygous point mutation in the GH1 promoter (c.-223C>T) leads to reduced GH1 expression in siblings with isolated GH deficiency (IGHD).

CONTEXT: Mutations in the GH1 promoter are a rare cause of isolated growth hormone deficiency (IGHD). OBJECTIVE: To identify the molecular aetiology of a family with IGHD. DESIGN: DNA sequencing, electromobility shift (EMSA) and luciferase reporter assays. SETTING: University Hospital. PATIENTS: Three siblings (2M) born to consanguineous parents presented with IGHD with normal pituitary on MRI. METHODS: The GH1 proximal promoter, locus control region, five exons and four introns as well as GHRHR gene were sequenced in genomic DNA by Sanger method. DNA-protein interaction was evaluated by EMSA in nuclear extracts of GH3 pituitary cells. Dual-luciferase reporter assays were performed in cells transiently transfected with plasmids containing four different combinations of GH1 allelic variants (AV). RESULTS: The patients harboured two homozygous variants (c.-185T>C and c.-223C>T) in the GH1 promoter within a highly conserved region and predicted binding sites for POU1F1/SP1 and SP1 respectively. The parents and brother were carriers and these variants were absent in 100 controls. EMSA demonstrated absent binding of GH3 nuclear extract to the c.-223C>T variant and normal binding of both POU1F1 protein and GH3 nuclear extract to the c.-185T>C variant. In contrast to GH1 promoter with AV only at c.-185, the GH1 promoter containing the AV only at c.-223 and at both positions drove significantly less expression of luciferase compared with the promoter containing either positions wild type in luciferase reporter assays. CONCLUSION: To our knowledge, c.-223C>T is the first homozygous point mutation in the GH1 promoter that leads to short stature due to IGHD.

FGFR1 and PROKR2 rare variants found in patients with combined pituitary hormone deficiencies.

The genetic aetiology of congenital hypopituitarism (CH) is not entirely elucidated. FGFR1 and PROKR2 loss-of-function mutations are classically involved in hypogonadotrophic hypogonadism (HH), however, due to the clinical and genetic overlap of HH and CH; these genes may also be involved in the pathogenesis of CH. Using a candidate gene approach, we screened 156 Brazilian patients with combined pituitary hormone deficiencies (CPHD) for loss-of-function mutations in FGFR1 and PROKR2. We identified three FGFR1 variants (p.Arg448Trp, p.Ser107Leu and p.Pro772Ser) in four unrelated patients (two males) and two PROKR2 variants (p.Arg85Cys and p.Arg248Glu) in two unrelated female patients. Five of the six patients harbouring the variants had a first-degree relative that was an unaffected carrier of it. Results of functional studies indicated that the new FGFR1 variant p.Arg448Trp is a loss-of-function variant, while p.Ser107Leu and p.Pro772Ser present signalling activity similar to the wild-type form. Regarding PROKR2 variants, results from previous functional studies indicated that p.Arg85Cys moderately compromises receptor signalling through both MAPK and Ca(2) (+) pathways while p.Arg248Glu decreases calcium mobilization but has normal MAPK activity. The presence of loss-of-function variants of FGFR1 and PROKR2 in our patients with CPHD is indicative of an adjuvant and/or modifier effect of these rare variants on the phenotype. The presence of the same variants in unaffected relatives implies that they cannot solely cause the phenotype. Other associated genetic and/or environmental modifiers may play a role in the aetiology of this condition.

Frequent development of combined pituitary hormone deficiency in patients initially diagnosed as isolated growth hormone deficiency: a long term follow-up of patients from a single center.

BACKGROUND: Children initially diagnosed with isolated GH deficiency (IGHD) have a variable rate to progress to combined pituitary hormone deficiency (CPHD) during follow-up. OBJECTIVE: To evaluate the development of CPHD in a group of childhood-onset IGHD followed at a single tertiary center over a long period of time. PATIENTS AND METHODS: We retrospectively analyzed data from 83 patients initially diagnosed as IGHD with a mean follow-up of 15.2 years. The Kaplan-Meier method and Cox regression analysis was used to estimate the temporal progression and to identify risk factors to development of CPHD over time. RESULTS: From 83 patients initially with IGHD, 37 (45%) developed CPHD after a median time of follow up of 5.4 years (range from 1.2 to 21 years). LH and FSH deficiencies were the most common pituitary hormone (38%) deficiencies developed followed by TSH (31%), ACTH (12%) and ADH deficiency (5%). ADH deficiency (3.1 ± 1 years from GHD diagnosis) presented earlier and ACTH deficiency (9.3 ± 3.5 years) presented later during follow up compared to LH/FSH (8.3 ± 4 years) and TSH (7.5 ± 5.6 years) deficiencies. In a Cox regression model, pituitary stalk abnormalities was the strongest risk factor for the development of CPHD (hazard ratio of 3.28; p = 0.002). CONCLUSION: Our study indicated a high frequency of development of CPHD in patients initially diagnosed as IGHD at childhood. Half of our patients with IGHD developed the second hormone deficiency after 5 years of diagnosis, reinforcing the need for lifelong monitoring of pituitary function in these patients.

Autosomal recessive form of isolated growth hormone deficiency is more frequent than the autosomal dominant form in a Brazilian cohort.

BACKGROUND: In most studies, the autosomal dominant (type II) form of isolated growth hormone deficiency (IGHD) has been more frequent than the autosomal recessive (type I) form. Our aim was to assess defects in the GH1 in short Brazilian children with different GH secretion status. SUBJECTS AND METHODS: We selected 135 children with postnatal short stature and classified according to the highest GH peak at stimulation tests in: severe IGHD (peak GH≤3.3 µg/L, n=38, all with normal pituitary magnetic resonance imaging); GH peak between 3.3 and 10 µg/L (n=76); and GH peak >10 µg/L (n=21). The entire coding region of GH1 was sequenced and complete GH1 deletions were assessed by Multiplex Ligation Dependent Probe Amplification and restriction enzyme digestion. RESULTS: Patients with severe IGHD had a higher frequency of consanguinity, were shorter, had lower levels of IGF-1 and IGFBP-3, and despite treatment with lower GH doses had a greater growth response than patients with GH peak ≥3.3 µg/L. Mutations were found only in patients with severe IGHD (GH peak<3.3 µg/L). Eight patients had autosomal recessive IGHD: Seven patients were homozygous for GH1 deletions and one patient was compound heterozygous for a GH1 deletion and the novel c.171+5G>C point mutation in intron 2, predicted to abolish the donor splice site. Only one patient, who was heterozygous for the c.291+1G>T mutation located at the universal donor splice site of intron 3 and predicts exon 3 skipping, had an autosomal dominant form. CONCLUSION: Analysis of GH1 in a cohort of Brazilian patients revealed that the autosomal recessive form of IGHD was more common than the dominant one, and both were found only in severe IGHD.

Genome-wide screening of copy number variants in children born small for gestational age reveals several candidate genes involved in growth pathways.

BACKGROUND: The etiology of prenatal-onset short stature with postnatal persistence is heterogeneous. Submicroscopic chromosomal imbalances, known as copy number variants (CNVs), may play a role in growth disorders. OBJECTIVE: To analyze the CNVs present in a group of patients born small for gestational age (SGA) without a known cause. PATIENTS AND METHODS: A total of 51 patients with prenatal and postnatal growth retardation associated with dysmorphic features and/or developmental delay, but without criteria for the diagnosis of known syndromes, were selected. Array-based comparative genomic hybridization was performed using DNA obtained from all patients. The pathogenicity of CNVs was assessed by considering the following criteria: inheritance; gene content; overlap with genomic coordinates for a known genomic imbalance syndrome; and overlap with CNVs previously identified in other patients with prenatal-onset short stature. RESULTS: In 17 of the 51 patients, 18 CNVs were identified. None of these imbalances has been reported in healthy individuals. Nine CNVs, found in eight patients (16%), were categorized as pathogenic or probably pathogenic. Deletions found in three patients overlapped with known microdeletion syndromes (4q, 10q26, and 22q11.2). These imbalances are de novo, gene rich and affect several candidate genes or genomic regions that may be involved in the mechanisms of growth regulation. CONCLUSION: Pathogenic CNVs in the selected patients born SGA were common (at least 16%), showing that rare CNVs are probably among the genetic causes of short stature in SGA patients and revealing genomic regions possibly implicated in this condition.

Relatively high frequency of non-synonymous GLI2 variants in patients with congenital hypopituitarism without holoprosencephaly.

OBJECTIVE: GLI2 is a downstream transcription factor in Sonic Hedgehog signalling, acting early in ventral forebrain and pituitary development. Heterozygous nonsense GLI2 mutations have been reported in patients with isolated or combined pituitary hormone deficiency (CPHD), with or without holoprosencephaly. The aim of this study was to screen for GLI2 mutations in a large cohort of patients with congenital GH deficiency. DESIGN AND PATIENTS: The GLI2 coding region of 41 patients with severe isolated GH deficiency (IGHD) and 136 patients with CPHD was amplified by PCR using intronic primers and sequenced. The frequency of GLI2 variants was verified in up to 155 Brazilian controls and in the 1000 Genomes database. The consequences of allelic variants were analysed by the Polyphen, SIFT, Mutationtaster and SNAP prediction sites. RESULTS: Eighteen different heterozygous non-synonymous GLI2 variants were identified in 24 patients. Twenty-three patients had CPHD and one had IGHD. Two patients had additional diabetes insipidus, indicating deficiencies of anterior and posterior pituitary lobes. The posterior pituitary lobe on MRI was ectopic in 16, not visible in 4, normally placed in 2 and imaging was not available in two patients, but there were no signs of holoprosencephaly. Sixteen GLI2 variants were considered deleterious in at least one of the prediction sites. CONCLUSIONS: A relatively high frequency of non-synonymous GLI2 variants was identified in patients with congenital GH deficiency without other brain defects, and most of these patients presented with CPHD and an ectopic posterior pituitary lobe. In vitro functional assays may contribute to ascertain the deleterious consequences of these variants.